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  • Audible Audio (.aa) file spec?

    - by Adam
    Does anyone know of a good resource on the Audible Audio (.aa) file spec? I'm trying to write a program that can use them, if no one knows of a resource, any tips on reverse engineering the spec my self? I opened it up in a Hex editor and poked around, looks like an MP3 but with a ton more header info.

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  • Best Java obfuscator ?

    - by Xinus
    I am developing a security software and want to obfuscate my java code so it will become impossible to reverse engineer. What is the most reliable java obfuscator ?

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  • SCOM 2012 DNS Forwarder Availability Monitor

    - by Massimo
    Background: I have an environment with two different AD domains, each in its own forest, each with two Windows Server 2008 R2 domain controllers acting as DNS servers. There is no trust between the domains. Each DNS server manages the main DNS zone for its AD domain, and then some other zones, including the reverse lookup zone for its IP subnets; all zones are AD-integrated; all DNS servers which manages a zone are correctly listed as authoritative name servers for that zone. So, the situation is like this (using fake names and IP addresses): Domain A: DNS domain: a.dom IP subnet: 192.168.1.X DC/DNS Servers: serverA1.a.dom (192.168.1.1) and serverA2.a.dom (192.168.1.2) Authoritative zones: a.dom, 1.168.192.in-addr.arpa, somezone.local Domain B: DNS domain: b.dom IP subnet: 10.0.0.X DC/DNS Servers: serverB1.b.dom (10.0.0.1) and serverB2.b.dom (10.0.0.2) Authoritative zones: b.dom, 0.0.10.in-addr.arpa, someotherzone.local DNS servers in domain A have conditional forwarders defined for each zone managed by DNS servers in domain B, forwarding to both domain B's DNS servers; DNS servers in domain B have the opposite configuration. All forwarders are stored in Active Directory. All is working perfectly, and computers in each domain can resolve forward and reverse DNS queries for both domains, using their domain's DNS servers. The problem: I have SCOM 2012 deployed in domain A, with the SCOM agent installed on both DCs; the management packs for Active Directory and DNS Server are installed and up-to-date. I have a series of alerts like the following ones on both domain controllers; each alert is generated for each forwarded zone and for each forwarded server: Forwarder someotherzone.local (10.0.0.1) cannot resolve the host name 192.168.1.1,someotherzone.local for serverA1.a.dom Forwarder someotherzone.local (10.0.0.2) cannot resolve the host name 192.168.1.1,someotherzone.local for serverA1.a.dom Forwarder someotherzone.local (10.0.0.1) cannot resolve the host name 192.168.1.2,someotherzone.local for serverA2.a.dom Forwarder someotherzone.local (10.0.0.2) cannot resolve the host name 192.168.1.2,someotherzone.local for serverA2.a.dom Forwarder 0.0.10.in-addr.arpa (10.0.0.1) cannot resolve the host name 192.168.1.1,0.0.10.in-addr.arpa for serverA1.a.dom Forwarder 0.0.10.in-addr.arpa (10.0.0.2) cannot resolve the host name 192.168.1.1,0.0.10.in-addr.arpa for serverA1.a.dom Forwarder 0.0.10.in-addr.arpa (10.0.0.1) cannot resolve the host name 192.168.1.2,0.0.10.in-addr.arpa for serverA2.a.dom Forwarder 0.0.10.in-addr.arpa (10.0.0.2) cannot resolve the host name 192.168.1.2,0.0.10.in-addr.arpa for serverA2.a.dom The only exception is the main AD DNS zone managed by domain B's DNS servers (b.dom): for that conditional forwarder, no alert is generated and the forwarder availability monitor is green. Ok, what does this mean? What are those monitors trying to tell me? What are they checking? What's actually wrong? And why there is no error for the "b.dom" zone, which is configured in the exact same way as the other ones, both as a zone in domain B's DNS servers and as a forwarder in domain A's DNS servers?

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  • bind9 DNS Ubuntu names pingible on server, but not on Windows Machines?

    - by leeand00
    I setup a DNS server today on Ubuntu, following this tutorial. My intent was to setup my network for dns-name resolving on the private LAN within a single zone (nothing fancy I just want name resolution). I've tested the setup on the DNS server machine itself, and I can ping all the machines listed in the configuration file. I've also configured the Windows Machines on my network, and for some reason they are incapable of pinging by names as was possible on the DNS Server itself. I've tried running nslookup on the Windows DNS clients and I receive and error mentioning the address of the DNS server. DNS forwarding works fine, I'm not having any trouble accessing the internet, the problem only lies within accessing names within the private LAN. Here are my configuration files: options { directory "/var/cache/bind"; // If there is a firewall between you and nameservers you want // to talk to, you may need to fix the firewall to allow multiple // ports to talk. See http://www.kb.cert.org/vuls/id/800113 // If your ISP provided one or more IP addresses for stable // nameservers, you probably want to use them as forwarders. // Uncomment the following block, and insert the addresses replacing // the all-0's placeholder. // forwarders { // 0.0.0.0; // }; forwarders { 8.8.8.8; 8.8.8.4; 74.242.0.12; //68.87.76.178; }; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; /etc/bind/named.conf.options zone "leerdomain.local" { type master; file "/etc/bind/zones/leerdomain.local.db"; notify no; }; zone "2.168.192.in-addr.arpa" { type master; file "/etc/bind/zones/rev.2.168.192.in-addr.arpa"; notify no; }; /etc/bind/named.conf.local Lookup: $TTL 3D @ IN SOA ns.leerdomain.local. admin.leerdomain.local. ( 2010011001 28800 3600 604800 38400 ); leerdomain.local. IN NS ns.leerdomain.local. ns IN A 192.168.2.9 asus IN A 192.168.2.254 www IN CNAME asus vaio IN A 192.168.2.253 iptouch IN A 192.168.2.252 toshiba IN A 192.168.2.251 gw IN A 192.168.2.1 TXT "Network Gateway" /etc/bind/zones/leerdomain.local.db (Validates fine with named-checkzone when validating zone leerdomain.local) Reverse Lookup: $TTL 3D @ IN SOA ns.leerdomain.local. admin.leerdomain.local. ( 201001101 28800 604800 604800 86400 ) IN NS ns.leerdomain.local. 1 IN PTR gw.leerdomain.local. 254 IN PTR asus.leerdomain.local. 253 IN PTR vaio.leerdomain.local. 252 IN PTR iptouch.leerdomain.local. 251 IN PTR toshiba.leerdomain.local. /etc/bind/zones/rev.2.168.192.in-addr.arpa *(Does not validate with named-checkzone when validating zone leerdomain.local gives an error of: zone leerdomain.local/IN: NS 'ns.leerdomain.local' has no address records (A or AAAA) zone leerdomain.local/IN: not loaded due to errors. * Despite not validating bind9 starts without errors in /var/log/syslog I've also configured a few of the windows machines on my network to have the static ip as specified in the lookup and reverse lookup config files. i.e. Using nslookup yields the following results: C:\Users\leeand00>nslookup ns Server: UnKnown Address: 192.168.2.9 *** UnKnown can't find ns: Non-existent domain C:\Users\leeand00>nslookup gw Server: UnKnown Address: 192.168.2.9 Name: gw. Additionally trying to ping by name also fails on machines that are not the DNS Server. Is there something wrong with my configuration of either the nameserver or the Windows Boxes that is keeping me from accessing other machines using names?

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  • Excel "Remove Duplicates" feature does not remove all duplicates

    - by raph82
    When the Data ToolsRemove Duplicates command is used on the following list, some duplicates are not removed: Key 46509 46509 51442 51442 73367 73367 80048 80048 88396 88396 102576 102576 108095 108095 118613 118613 127224 127224 137549 137549 140164 140164 151679 151679 152975 152975 154986 154986 167715 167715 169166 169166 170427 170427 176303 176303 187038 187038 199856 199856 206589 206589 225371 225371 229767 229767 230680 230680 245333 245333 253697 253697 256002 256002 262094 262094 273060 273060 275584 275584 285569 285569 301930 301930 304993 304993 305965 305965 307299 307299 311438 311438 314461 314461 340545 340545 344517 344517 355035 355035 358387 358387 359982 359982 363904 363904 368642 368642 378666 378666 378744 378744 382396 382396 393542 393542 394320 394320 395258 395258 402047 402047 421796 421796 427972 427972 442651 442651 442654 442654 445786 445786 447124 447124 456682 456682 467303 467303 470437 470437 476340 476340 480976 480976 481450 481450 498967 498967 516068 516068 517592 517592 522621 522621 524678 524678 529405 529405 532909 532909 535096 535096 540835 540835 553197 553197 566893 566893 567730 567730 570751 570751 572259 572259 581701 581701 589753 589753 597923 597923 602282 602282 612011 612011 643774 643774 649471 649471 654159 654159 661681 661681 680578 680578 709714 709714 728036 728036 728680 728680 740252 740252 750843 750843 763430 763430 777724 777724 777870 777870 779703 779703 787034 787034 789776 789776 793859 793859 798479 798479 812410 812410 816599 816599 820169 820169 821236 821236 833511 833511 833701 833701 845925 845925 854408 854408 882853 882853 891710 891710 906251 906251 929802 929802 982039 982039 984503 984503 984539 984539 987889 987889 997188 997188 1002869 1002869 1018493 1018493 1020735 1020735 1028780 1028780 1032460 1032460 1047306 1047306 1052136 1052136 1054482 1054482 1062633 1062633 1066509 1066509 1069500 1069500 1075339 1075339 1082282 1082282 1100206 1100206 1105407 1105407 1111409 1111409 1112175 1112175 1112407 1112407 1113400 1113400 1117243 1117243 1121732 1121732 1152461 1152461 1153727 1153727 1157252 1157252 1163384 1163384 1195324 1195324 1197373 1197373 1201828 1201828 1202786 1202786 1216328 1216328 1223541 1223541 1225848 1225848 1228595 1228595 1239281 1239281 1264378 1264378 1267348 1267348 1291510 1291510 1309891 1309891 1321106 1321106 1322886 1322886 1327690 1327690 1344145 1344145 1346250 1346250 1352350 1352350 1357920 1357920 1363386 1363386 1365046 1365046 1370383 1370383 1376666 1376666 1383834 1383834 1414472 1414472 1418967 1418967 1419811 1419811 1421587 1421587 1432639 1432639 1442854 1442854 1455236 1455236 1461896 1461896 1466376 1466376 1477670 1477670 1480154 1480154 1481801 1481801 1498209 1498209 1504776 1504776 1511904 1511904 1017854_447 1017854_447 1085496_19 1085496_19 1280601_77 1280601_77 1350662_135 1350662_135 141944_382 141944_382 1525893_483 1525893_483 455968_177 455968_177 469495_157 469495_157 641583_74 641583_74 704267_63 704267_63 709992_199 709992_199 819399_224 819399_224 832188_358 832188_358 857189_467 857189_467 898328_334 898328_334 91033_245 91033_245 960992_341 960992_341 999706_361 999706_361 BLA1048669 BLA1048669 BLA1052457 BLA1052457 BLA1055176 BLA1055176 BLA1060585 BLA1060585 BLA1067125 BLA1067125 BLA107601 BLA107601 BLA1087509 BLA1087509 BLA1097390 BLA1097390 BLA1122471 BLA1122471 BLA1126436 BLA1126436 BLA112694 BLA112694 BLA1148652 BLA1148652 BLA1149504 BLA1149504 BLA1155256 BLA1155256 BLA1222348 BLA1222348 BLA1225575 BLA1225575 BLA1227779 BLA1227779 BLA124071 BLA124071 BLA1247411 BLA1247411 BLA1258830 BLA1258830 BLA1281625 BLA1281625 BLA128165 BLA128165 BLA1305848 BLA1305848 BLA1307751 BLA1307751 BLA130926 BLA130926 BLA1334270 BLA1334270 BLA1335674 BLA1335674 BLA1340102 BLA1340102 BLA1345080 BLA1345080 BLA1353398 BLA1353398 BLA1369834 BLA1369834 BLA1424977 BLA1424977 BLA142669 BLA142669 BLA1429760 BLA1429760 BLA1443592 BLA1443592 BLA1447085 BLA1447085 BLA1453639 BLA1453639 BLA1456355 BLA1456355 BLA1458745 BLA1458745 BLA148663 BLA148663 BLA1494220 BLA1494220 BLA1522880 BLA1522880 BLA152562 BLA152562 BLA1548628 BLA1548628 BLA182644 BLA182644 BLA186707 BLA186707 BLA188073 BLA188073 BLA199127 BLA199127 BLA207148 BLA207148 BLA209939 BLA209939 BLA232119 BLA232119 BLA240725 BLA240725 BLA267275 BLA267275 BLA303829 BLA303829 BLA346044 BLA346044 BLA348268 BLA348268 BLA367863 BLA367863 BLA386897 BLA386897 BLA390799 BLA390799 BLA415724 BLA415724 BLA425291 BLA425291 BLA427093 BLA427093 BLA462355 BLA462355 BLA46821 BLA46821 BLA477637 BLA477637 BLA501111 BLA501111 BLA522126 BLA522126 BLA530906 BLA530906 BLA576525 BLA576525 BLA639361 BLA639361 BLA644530 BLA644530 BLA65754 BLA65754 BLA670003 BLA670003 BLA687525 BLA687525 BLA709367 BLA709367 BLA714281 BLA714281 BLA719328 BLA719328 BLA736457 BLA736457 BLA759669 BLA759669 BLA76056 BLA76056 BLA767666 BLA767666 BLA780853 BLA780853 BLA793029 BLA793029 BLA796639 BLA796639 BLA803743 BLA803743 BLA815298 BLA815298 BLA828243 BLA828243 BLA864030 BLA864030 BLA864110 BLA864110 BLA882892 BLA882892 BLA885665 BLA885665 BLA897478 BLA897478 BLA903861 BLA903861 BLA91627 BLA91627 BLA925523 BLA925523 BLA928243 BLA928243 BLA932395 BLA932395 BLA935341 BLA935341 BLA940705 BLA940705 BLA966386 BLA966386 A message is displayed indicating 293 duplicate values were removed and 307 unique values remain. 7 duplicates are not removed: 1280601_77 1525893_483 455968_177 469495_157 641583_74 704267_63 709992_199 The initial list consist of Excel-ordered values of: numbers between 40,000 and 1,500,000 numbers in the same range with and added _ and a 1-999 suffix numbers in the same range prefixed with BLA Each value is present exactly twice. There are no formula involved. I already checked for extra spaces. Immediately reapplying the Remove Duplicates command does not remove the remaining duplicate values. Reapplying the Remove Duplicates command after a reverse-sort seems to remove the remaining duplicates. Reverse-sorting before using the first Remove Duplicates changes the result (213 duplicate values removed and 387 unique values remained), only in the non-suffixed non-prefixed group. Can you reproduce this bug in Excel 2007 like I do? What triggers it? Could it the composite (numbers and text) data set? I'm not looking for alternatives. I want to know when not to use the feature and revert to already known (Excel 2003 era) alternatives.

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  • Simple Cisco ASA 5505 config issue

    - by Ben Sebborn
    I have a Cisco ASA setup with two interfaces: inside: 192.168.2.254 / 255.255.255.0 SecLevel:100 outside: 192.168.3.250 / 255.255.255.0 SecLevel: 0 I have a static route setup to allow PCs on the inside network to access the internet via a gateway on the outside interface (3.254): outside 0.0.0.0 0.0.0.0 192.168.3.254 This all works fine. I now need to be able to access a PC on the outside interface (3.253) from a PC on the inside interface on port 35300. I understand I should be able to do this with no problems, as I'm going from a higher security level to a lower one. However I can't get any connection. Do I need to set up a seperate static route? Perhaps the route above is overriding what I need to be able to do (is it routing ALL traffic through the gateway?) Any advice on how to do this would be apprecaited. I am configuring this via ASDM but the config can be seen as below: Result of the command: "show running-config" : Saved : ASA Version 8.2(5) ! hostname ciscoasa domain-name xxx.internal names name 192.168.2.201 dev.xxx.internal description Internal Dev server name 192.168.2.200 Newserver ! interface Ethernet0/0 switchport access vlan 2 ! interface Ethernet0/1 ! interface Ethernet0/2 ! interface Ethernet0/3 shutdown ! interface Ethernet0/4 shutdown ! interface Ethernet0/5 shutdown ! interface Ethernet0/6 shutdown ! interface Ethernet0/7 shutdown ! interface Vlan1 nameif inside security-level 100 ip address 192.168.2.254 255.255.255.0 ! interface Vlan2 nameif outside security-level 0 ip address 192.168.3.250 255.255.255.0 ! ! time-range Workingtime periodic weekdays 9:00 to 18:00 ! ftp mode passive clock timezone GMT/BST 0 clock summer-time GMT/BDT recurring last Sun Mar 1:00 last Sun Oct 2:00 dns domain-lookup inside dns server-group DefaultDNS name-server Newserver domain-name xxx.internal same-security-traffic permit inter-interface object-group service Mysql tcp port-object eq 3306 object-group protocol TCPUDP protocol-object udp protocol-object tcp access-list inside_access_in extended permit ip any any access-list outside_access_in remark ENABLES OUTSDIE ACCESS TO DEV SERVER! access-list outside_access_in extended permit tcp any interface outside eq www time-range Workingtime inactive access-list outside_access_in extended permit tcp host www-1.xxx.com interface outside eq ssh access-list inside_access_in_1 extended permit tcp any any eq www access-list inside_access_in_1 extended permit tcp any any eq https access-list inside_access_in_1 remark Connect to SSH services access-list inside_access_in_1 extended permit tcp any any eq ssh access-list inside_access_in_1 remark Connect to mysql server access-list inside_access_in_1 extended permit tcp any host mysql.xxx.com object-group Mysql access-list inside_access_in_1 extended permit tcp any host mysql.xxx.com eq 3312 access-list inside_access_in_1 extended permit object-group TCPUDP host Newserver any eq domain access-list inside_access_in_1 extended permit icmp any any access-list inside_access_in_1 remark Draytek Admin access-list inside_access_in_1 extended permit tcp any 192.168.3.0 255.255.255.0 eq 4433 access-list inside_access_in_1 remark Phone System access-list inside_access_in_1 extended permit tcp any 192.168.3.0 255.255.255.0 eq 35300 log disable pager lines 24 logging enable logging asdm warnings logging from-address [email protected] logging recipient-address [email protected] level errors mtu inside 1500 mtu outside 1500 ip verify reverse-path interface inside ip verify reverse-path interface outside ipv6 access-list inside_access_ipv6_in permit tcp any any eq www ipv6 access-list inside_access_ipv6_in permit tcp any any eq https ipv6 access-list inside_access_ipv6_in permit tcp any any eq ssh ipv6 access-list inside_access_ipv6_in permit icmp6 any any icmp unreachable rate-limit 1 burst-size 1 icmp permit any outside no asdm history enable arp timeout 14400 global (outside) 1 interface nat (inside) 1 0.0.0.0 0.0.0.0 static (inside,outside) tcp interface www dev.xxx.internal www netmask 255.255.255.255 static (inside,outside) tcp interface ssh dev.xxx.internal ssh netmask 255.255.255.255 access-group inside_access_in in interface inside control-plane access-group inside_access_in_1 in interface inside access-group inside_access_ipv6_in in interface inside access-group outside_access_in in interface outside route outside 0.0.0.0 0.0.0.0 192.168.3.254 10 route outside 192.168.3.252 255.255.255.255 192.168.3.252 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute timeout tcp-proxy-reassembly 0:01:00 timeout floating-conn 0:00:00 dynamic-access-policy-record DfltAccessPolicy aaa authentication telnet console LOCAL aaa authentication enable console LOCAL

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  • Forwarding rsyslog to syslog-ng, with FQDN and facility separation

    - by Joshua Miller
    I'm attempting to configure my rsyslog clients to forward messages to my syslog-ng log repository systems. Forwarding messages works "out of the box", but my clients are logging short names, not FQDNs. As a result the messages on the syslog repo use short names as well, which is a problem because one can't determine which system the message originated from easily. My clients get their names through DHCP / DNS. I've tried a number of solutions trying to get this working, but without success. I'm using rsyslog 4.6.2 and syslog-ng 3.2.5. I've tried setting $PreserveFQDN on as the first directive in /etc/rsyslog.conf (and restarting rsyslog of course). It seems to have no effect. hostname --fqdn on the client returns the proper FQDN, so the problem isn't whether the system can actually figure out its own FQDN. $LocalHostName <fqdn> looked promising, but this directive isn't available in my version of rsyslog (Available since 4.7.4+, 5.7.3+, 6.1.3+). Upgrading isn't an option at the moment. Configuring the syslog-ng server to populate names based on reverse lookups via DNS isn't an option. There are complexities with reverse DNS and the public cloud. Specifying for the forwarder to use a custom template seems like a viable option at first glance. I can specify the following, which causes local logging to begin using the FQDN on the syslog-ng repo. $template MyTemplate, "%timestamp% <FQDN> %syslogtag%%msg%" $ActionForwardDefaultTemplate MyTemplate However, when I put this in place syslog-ng seems to be unable to categorize messages by facility or priority. Messages come in as FQDN, but everything is put in to user.log. When I don't use the custom template, messages are properly categorized under facility and priority, but with the short name. So, in summary, if I manually trick rsyslog into including the FQDN, priority and facility becomes lost details to syslog-ng. How can I get rsyslog to do FQDN logging which works properly going to a syslog-ng repository? rsyslog client config: $ModLoad imuxsock.so # provides support for local system logging (e.g. via logger command) $ModLoad imklog.so # provides kernel logging support (previously done by rklogd) $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg * uucp,news.crit /var/log/spooler local7.* /var/log/boot.log $WorkDirectory /var/spool/rsyslog # where to place spool files $ActionQueueFileName fwdRule1 # unique name prefix for spool files $ActionQueueMaxDiskSpace 1g # 1gb space limit (use as much as possible) $ActionQueueSaveOnShutdown on # save messages to disk on shutdown $ActionQueueType LinkedList # run asynchronously $ActionResumeRetryCount -1 # infinite retries if host is down *.* @syslog-ng1.example.com *.* @syslog-ng2.example.com syslog-ng configuration (abridged for brevity): options { flush_lines (0); time_reopen (10); log_fifo_size (1000); long_hostnames (off); use_dns (no); use_fqdn (yes); create_dirs (no); keep_hostname (yes); }; source src { unix-stream("/dev/log"); internal(); udp(ip(0.0.0.0) port(514)); }; destination per_host_destination { file( "/var/log/syslog-ng/devices/$HOST/$FACILITY.log" owner("root") group("root") perm(0644) dir_owner(root) dir_group(root) dir_perm(0775) create_dirs(yes)); }; log { source(src); destination(per_facility_destination); };

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  • Why don't I just build the whole web app in Javascript and Javascript HTML Templates?

    - by viatropos
    I'm getting to the point on an app where I need to start caching things, and it got me thinking... In some parts of the app, I render table rows (jqGrid, slickgrid, etc.) or fancy div rows (like in the New Twitter) by grabbing pure JSON and running it through something like Mustache, jquery.tmpl, etc. In other parts of the app, I just render the info in pure HTML (server-side HAML templates), and if there's searching/paginating, I just go to a new URL and load a new HTML page. Now the problem is in caching and maintainability. On one hand I'm thinking, if everything was built using Javascript HTML Templates, then my app would serve just an HTML layout/shell, and a bunch of JSON. If you look at the Facebook and Twitter HTML source, that's basically what they're doing (95% json/javascript, 5% html). This would make it so my app only needed to cache JSON (pages, actions, and/or records). Which means you'd hit the cache no matter if you were some remote api developer accessing a JSON api, or the strait web app. That is, I don't need 2 caches, one for the JSON, one for the HTML. That seems like it'd cut my cache store down in half, and streamline things a little bit. On the other hand, I'm thinking, from what I've seen/experienced, generating static HTML server-side, and caching that, seems to be much better performance wise cross-browser; you get the graphics instantly and don't have to wait that split-second for javascript to render it. StackOverflow seems to do everything in plain HTML, and you can tell... everything appears at once. Notice how though on twitter.com, the page is blank for .5-1 seconds, and the page chunks in: the javascript has to render the json. The downside with this is that, for anything dynamic (like endless scrolling, or grids), I'd have to create javascript templates anyway... so now I have server-side HAML templates, client-side javascript templates, and a lot more to cache. My question is, is there any consensus on how to approach this? What are the benefits and drawbacks from your experience of mixing the two versus going 100% with one over the other? Update: Some reasons that factor into why I haven't yet made the decision to go with 100% javascript templating are: Performance. Haven't formally tested, but from what I've seen, raw html renders faster and more fluidly than javascript-generated html cross-browser. Plus, I'm not sure how mobile devices handle dynamic html performance-wise. Testing. I have a lot of integration tests that work well with static HTML, so switching to javascript-only would require 1) more focused pure-javascript testing (jasmine), and 2) integrating javascript into capybara integration tests. This is just a matter of time and work, but it's probably significant. Maintenance. Getting rid of HAML. I love HAML, it's so easy to write, it prints pretty HTML... It makes code clean, it makes maintenance easy. Going with javascript, there's nothing as concise. SEO. I know google handles the ajax /#!/path, but haven't grasped how this will affect other search engines and how older browsers handle it. Seems like it'd require a significant setup.

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  • Opinions on Copy Protection / Software Licensing via phoning home?

    - by Jakobud
    I'm developing some software that I'm going to eventually sell. I've been thinking about different copy protection mechanisms, both custom and 3rd party. I know that no copy protection is 100% full-proof, but I need to at least try. So I'm looking for some opinions to my approach I'm thinking about: One method I'm thinking about is just having my software connect to a remote server when it starts up, in order to verify the license based off the MAC address of the ethernet port. I'm not sure if the server would be running a MySQL database that retrieves the license information, or what... Is there a more simple way? Maybe some type of encrypted file that is read? I would make the software still work if it can't connect to the server. I don't want to lock someone out just because they don't have internet access at that moment in time. In case you are wondering, the software I'm developing is extremely internet/network dependant. So its actually quite unlikely that the user wouldn't have internet access when using it. Actually, its pretty useless without internet/network access. Anyone know what I would do about computers that have multiple MAC addresses? A lot of motherboards these days have 2 ethernet ports. And most laptops have 1 ethernet, 1 wifi and Bluetooth MAC addresses. I suppose I could just pick a MAC port and run with it. Not sure if it really matters A smarty and tricky user could determine the server that the software is connecting to and perhaps add it to their host file so that it always trys to connect to localhost. How likely do you think this is? And do you think its possible for the software to check if this is being done? I guess parsing of the host file could always work. Look for your server address in there and see if its connecting to localhost or something. I've considered dongles, but I'm trying to avoid them just because I know they are a pain to work with. Keeping them updated and possibly requiring the customer to run their own license server is a bit too much for me. I've experienced that and it's a bit of a pain that I wouldn't want to put my customers through. Also I'm trying to avoid that extra overhead cost of using 3rd party dongles. Also, I'm leaning toward connecting to a remote server to verify authentication as opposed to just sending the user some sort of license file because what happens when the user buys a new computer? I have to send them a replacement license file that will work with their new computer, but they will still be able to use it on their old computer as well. There is no way for me to 'de-authorize' their old computer without asking them to run some program on it or something. Also, one important note, with the software I would make it very clear to the user in the EULA that the software connects to a remote server to verify licensing and that no personal information is sent. I know I don't care much for software that does that kinda stuff without me knowing. Anyways, just looking for some opinions for people who have maybe gone down this kinda road. It seems like remote-server-dependent-software would be one of the most effective copy-protection mechanisms, not just because of difficulty of circumventing, but also could be pretty easy to manage the licenses on the developers end.

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  • Please clarify how create/update happens against child entities of an aggregate root

    - by christian
    After much reading and thinking as I begin to get my head wrapped around DDD, I am a bit confused about the best practices for dealing with complex hierarchies under an aggregate root. I think this is a FAQ but after reading countless examples and discussions, no one is quite talking about the issue I'm seeing. If I am aligned with the DDD thinking, entities below the aggregate root should be immutable. This is the crux of my trouble, so if that isn't correct, that is why I'm lost. Here is a fabricated example...hope it holds enough water to discuss. Consider an automobile insurance policy (I'm not in insurance, but this matches the language I hear when on the phone w/ my insurance company). Policy is clearly an entity. Within the policy, let's say we have Auto. Auto, for the sake of this example, only exists within a policy (maybe you could transfer an Auto to another policy, so this is potential for an aggregate as well, which changes Policy...but assume it simpler than that for now). Since an Auto cannot exist without a Policy, I think it should be an Entity but not a root. So Policy in this case is an aggregate root. Now, to create a Policy, let's assume it has to have at least one auto. This is where I get frustrated. Assume Auto is fairly complex, including many fields and maybe a child for where it is garaged (a Location). If I understand correctly, a "create Policy" constructor/factory would have to take as input an Auto or be restricted via a builder to not be created without this Auto. And the Auto's creation, since it is an entity, can't be done beforehand (because it is immutable? maybe this is just an incorrect interpretation). So you don't get to say new Auto and then setX, setY, add(Z). If Auto is more than somewhat trivial, you end up having to build a huge hierarchy of builders and such to try to manage creating an Auto within the context of the Policy. One more twist to this is later, after the Policy is created and one wishes to add another Auto...or update an existing Auto. Clearly, the Policy controls this...fine...but Policy.addAuto() won't quite fly because one can't just pass in a new Auto (right!?). Examples say things like Policy.addAuto(VIN, make, model, etc.) but are all so simple that that looks reasonable. But if this factory method approach falls apart with too many parameters (the entire Auto interface, conceivably) I need a solution. From that point in my thinking, I'm realizing that having a transient reference to an entity is OK. So, maybe it is fine to have a entity created outside of its parent within the aggregate in a transient environment, so maybe it is OK to say something like: auto = AutoFactory.createAuto(); auto.setX auto.setY or if sticking to immutability, AutoBuilder.new().setX().setY().build() and then have it get sorted out when you say Policy.addAuto(auto) This insurance example gets more interesting if you add Events, such as an Accident with its PolicyReports or RepairEstimates...some value objects but most entities that are all really meaningless outside the policy...at least for my simple example. The lifecycle of Policy with its growing hierarchy over time seems the fundamental picture I must draw before really starting to dig in...and it is more the factory concept or how the child entities get built/attached to an aggregate root that I haven't seen a solid example of. I think I'm close. Hope this is clear and not just a repeat FAQ that has answers all over the place.

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  • Displaying an image on a LED matrix with a Netduino

    - by Bertrand Le Roy
    In the previous post, we’ve been flipping bits manually on three ports of the Netduino to simulate the data, clock and latch pins that a shift register expected. We did all that in order to control one line of a LED matrix and create a simple Knight Rider effect. It was rightly pointed out in the comments that the Netduino has built-in knowledge of the sort of serial protocol that this shift register understands through a feature called SPI. That will of course make our code a whole lot simpler, but it will also make it a whole lot faster: writing to the Netduino ports is actually not that fast, whereas SPI is very, very fast. Unfortunately, the Netduino documentation for SPI is severely lacking. Instead, we’ve been reliably using the documentation for the Fez, another .NET microcontroller. To send data through SPI, we’ll just need  to move a few wires around and update the code. SPI uses pin D11 for writing, pin D12 for reading (which we won’t do) and pin D13 for the clock. The latch pin is a parameter that can be set by the user. This is very close to the wiring we had before (data on D11, clock on D12 and latch on D13). We just have to move the latch from D13 to D10, and the clock from D12 to D13. The code that controls the shift register has slimmed down considerably with that change. Here is the new version, which I invite you to compare with what we had before: public class ShiftRegister74HC595 { protected SPI Spi; public ShiftRegister74HC595(Cpu.Pin latchPin) : this(latchPin, SPI.SPI_module.SPI1) { } public ShiftRegister74HC595(Cpu.Pin latchPin, SPI.SPI_module spiModule) { var spiConfig = new SPI.Configuration( SPI_mod: spiModule, ChipSelect_Port: latchPin, ChipSelect_ActiveState: false, ChipSelect_SetupTime: 0, ChipSelect_HoldTime: 0, Clock_IdleState: false, Clock_Edge: true, Clock_RateKHz: 1000 ); Spi = new SPI(spiConfig); } public void Write(byte buffer) { Spi.Write(new[] {buffer}); } } All we have to do here is configure SPI. The write method couldn’t be any simpler. Everything is now handled in hardware by the Netduino. We set the frequency to 1MHz, which is largely sufficient for what we’ll be doing, but it could potentially go much higher. The shift register addresses the columns of the matrix. The rows are directly wired to ports D0 to D7 of the Netduino. The code writes to only one of those eight lines at a time, which will make it fast enough. The way an image is displayed is that we light the lines one after the other so fast that persistence of vision will give the illusion of a stable image: foreach (var bitmap in matrix.MatrixBitmap) { matrix.OnRow(row, bitmap, true); matrix.OnRow(row, bitmap, false); row++; } Now there is a twist here: we need to run this code as fast as possible in order to display the image with as little flicker as possible, but we’ll eventually have other things to do. In other words, we need the code driving the display to run in the background, except when we want to change what’s being displayed. Fortunately, the .NET Micro Framework supports multithreading. In our implementation, we’ve added an Initialize method that spins a new thread that is tied to the specific instance of the matrix it’s being called on. public LedMatrix Initialize() { DisplayThread = new Thread(() => DoDisplay(this)); DisplayThread.Start(); return this; } I quite like this way to spin a thread. As you may know, there is another, built-in way to contextualize a thread by passing an object into the Start method. For the method to work, the thread must have been constructed with a ParameterizedThreadStart delegate, which takes one parameter of type object. I like to use object as little as possible, so instead I’m constructing a closure with a Lambda, currying it with the current instance. This way, everything remains strongly-typed and there’s no casting to do. Note that this method would extend perfectly to several parameters. Of note as well is the return value of Initialize, a common technique to add some fluency to the API and enabling the matrix to be instantiated and initialized in a single line: using (var matrix = new LedMS88SR74HC595().Initialize()) The “using” in the previous line is because we have implemented IDisposable so that the matrix kills the thread and clears the display when the user code is done with it: public void Dispose() { Clear(); DisplayThread.Abort(); } Thanks to the multi-threaded version of the matrix driver class, we can treat the display as a simple bitmap with a very synchronous programming model: matrix.Set(someimage); while (button.Read()) { Thread.Sleep(10); } Here, the call into Set returns immediately and from the moment the bitmap is set, the background display thread will constantly continue refreshing no matter what happens in the main thread. That enables us to wait or read a button’s port on the main thread knowing that the current image will continue displaying unperturbed and without requiring manual refreshing. We’ve effectively hidden the implementation of the display behind a convenient, synchronous-looking API. Pretty neat, eh? Before I wrap up this post, I want to talk about one small caveat of using SPI rather than driving the shift register directly: when we got to the point where we could actually display images, we noticed that they were a mirror image of what we were sending in. Oh noes! Well, the reason for it is that SPI is sending the bits in a big-endian fashion, in other words backwards. Now sure you could fix that in software by writing some bit-level code to reverse the bits we’re sending in, but there is a far more efficient solution than that. We are doing hardware here, so we can simply reverse the order in which the outputs of the shift register are connected to the columns of the matrix. That’s switching 8 wires around once, as compared to doing bit operations every time we send a line to display. All right, so bringing it all together, here is the code we need to write to display two images in succession, separated by a press on the board’s button: var button = new InputPort(Pins.ONBOARD_SW1, false, Port.ResistorMode.Disabled); using (var matrix = new LedMS88SR74HC595().Initialize()) { // Oh, prototype is so sad! var sad = new byte[] { 0x66, 0x24, 0x00, 0x18, 0x00, 0x3C, 0x42, 0x81 }; DisplayAndWait(sad, matrix, button); // Let's make it smile! var smile = new byte[] { 0x42, 0x18, 0x18, 0x81, 0x7E, 0x3C, 0x18, 0x00 }; DisplayAndWait(smile, matrix, button); } And here is a video of the prototype running: The prototype in action I’ve added an artificial delay between the display of each row of the matrix to clearly show what’s otherwise happening very fast. This way, you can clearly see each of the two images being displayed line by line. Next time, we’ll do no hardware changes, focusing instead on building a nice programming model for the matrix, with sprites, text and hardware scrolling. Fun stuff. By the way, can any of my reader guess where we’re going with all that? The code for this prototype can be downloaded here: http://weblogs.asp.net/blogs/bleroy/Samples/NetduinoLedMatrixDriver.zip

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  • bluetooth not working on Ubuntu 13.10

    - by iacopo
    I upgrated ubuntu from 13.4 to 13.10 and my bluetooth stopped working. When I open bluetooth I'm able to put it ON but the visibility doesn't show anything and didn't detect any device. when I: dmesg | grep Blue [ 2.046249] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.046252] usb 3-1: Manufacturer: Bluetooth v2.0 [ 15.255710] Bluetooth: Core ver 2.16 [ 15.255748] Bluetooth: HCI device and connection manager initialized [ 15.255759] Bluetooth: HCI socket layer initialized [ 15.255765] Bluetooth: L2CAP socket layer initialized [ 15.255776] Bluetooth: SCO socket layer initialized [ 20.110379] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.110386] Bluetooth: BNEP filters: protocol multicast [ 20.110400] Bluetooth: BNEP socket layer initialized [ 20.120635] Bluetooth: RFCOMM TTY layer initialized [ 20.120656] Bluetooth: RFCOMM socket layer initialized [ 20.120660] Bluetooth: RFCOMM ver 1.11 when I digit: lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 0bc2:2300 Seagate RSS LLC Expansion Portable Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 002: ID 0e6a:6001 Megawin Technology Co., Ltd GEMBIRD Flexible keyboard KB-109F-B-DE Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 005 Device 002: ID 13ee:0001 MosArt Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode) Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub when I: hciconfig -a hci0: Type: BR/EDR Bus: USB BD Address: 00:1B:10:00:2A:EC ACL MTU: 1017:8 SCO MTU: 64:0 DOWN RX bytes:457 acl:0 sco:0 events:16 errors:0 TX bytes:68 acl:0 sco:0 commands:16 errors:0 Features: 0xff 0xff 0x8d 0xfe 0x9b 0xf9 0x00 0x80 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: Link mode: SLAVE ACCEPT when I digit: rfkill list 0: phy0: Wireless LAN Soft blocked: yes Hard blocked: no 1: hci0: Bluetooth Soft blocked: no Hard blocked: no when I digit: sudo gedit /etc/bluetooth/main.conf [General] # List of plugins that should not be loaded on bluetoothd startup #DisablePlugins = network,input # Default adaper name # %h - substituted for hostname # %d - substituted for adapter id Name = %h-%d # Default device class. Only the major and minor device class bits are # considered. Class = 0x000100 # How long to stay in discoverable mode before going back to non-discoverable # The value is in seconds. Default is 180, i.e. 3 minutes. # 0 = disable timer, i.e. stay discoverable forever DiscoverableTimeout = 0 # How long to stay in pairable mode before going back to non-discoverable # The value is in seconds. Default is 0. # 0 = disable timer, i.e. stay pairable forever PairableTimeout = 0 # Use some other page timeout than the controller default one # which is 16384 (10 seconds). PageTimeout = 8192 # Automatic connection for bonded devices driven by platform/user events. # If a platform plugin uses this mechanism, automatic connections will be # enabled during the interval defined below. Initially, this feature # intends to be used to establish connections to ATT channels. AutoConnectTimeout = 60 # What value should be assumed for the adapter Powered property when # SetProperty(Powered, ...) hasn't been called yet. Defaults to true InitiallyPowered = true # Remember the previously stored Powered state when initializing adapters RememberPowered = false # Use vendor id source (assigner), vendor, product and version information for # DID profile support. The values are separated by ":" and assigner, VID, PID # and version. # Possible vendor id source values: bluetooth, usb (defaults to usb) #DeviceID = bluetooth:1234:5678:abcd # Do reverse service discovery for previously unknown devices that connect to # us. This option is really only needed for qualification since the BITE tester # doesn't like us doing reverse SDP for some test cases (though there could in # theory be other useful purposes for this too). Defaults to true. ReverseServiceDiscovery = true # Enable name resolving after inquiry. Set it to 'false' if you don't need # remote devices name and want shorter discovery cycle. Defaults to 'true'. NameResolving = true # Enable runtime persistency of debug link keys. Default is false which # makes debug link keys valid only for the duration of the connection # that they were created for. DebugKeys = false # Enable the GATT functionality. Default is false EnableGatt = false when I digit: dmesg | grep Bluetooth [ 2.013041] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.013049] usb 3-1: Manufacturer: Bluetooth v2.0 [ 13.798293] Bluetooth: Core ver 2.16 [ 13.798338] Bluetooth: HCI device and connection manager initialized [ 13.798352] Bluetooth: HCI socket layer initialized [ 13.798357] Bluetooth: L2CAP socket layer initialized [ 13.798368] Bluetooth: SCO socket layer initialized [ 20.184162] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.184173] Bluetooth: BNEP filters: protocol multicast [ 20.184197] Bluetooth: BNEP socket layer initialized [ 20.238947] Bluetooth: RFCOMM TTY layer initialized [ 20.238983] Bluetooth: RFCOMM socket layer initialized [ 20.239018] Bluetooth: RFCOMM ver 1.11 When I digit: uname -a Linux casa-desktop 3.11.0-13-generic #20-Ubuntu SMP Wed Oct 23 07:38:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux When I digit: lsmod Module Size Used by parport_pc 32701 0 rfcomm 69070 4 bnep 19564 2 ppdev 17671 0 ip6t_REJECT 12910 1 xt_hl 12521 6 ip6t_rt 13507 3 nf_conntrack_ipv6 18938 9 nf_defrag_ipv6 34616 1 nf_conntrack_ipv6 ipt_REJECT 12541 1 xt_LOG 17718 8 xt_limit 12711 11 xt_tcpudp 12884 32 xt_addrtype 12635 4 nf_conntrack_ipv4 15012 9 nf_defrag_ipv4 12729 1 nf_conntrack_ipv4 xt_conntrack 12760 18 ip6table_filter 12815 1 ip6_tables 27025 1 ip6table_filter nf_conntrack_netbios_ns 12665 0 nf_conntrack_broadcast 12589 1 nf_conntrack_netbios_ns nf_nat_ftp 12741 0 nf_nat 26653 1 nf_nat_ftp kvm_amd 59958 0 nf_conntrack_ftp 18608 1 nf_nat_ftp kvm 431315 1 kvm_amd nf_conntrack 91736 8 nf_nat_ftp,nf_conntrack_netbios_ns,nf_nat,xt_conntrack,nf_conntrack_broadcast,nf_conntrack_ftp,nf_conntrack_ipv4,nf_conntrack_ipv6 iptable_filter 12810 1 crct10dif_pclmul 14289 0 crc32_pclmul 13113 0 ip_tables 27239 1 iptable_filter snd_hda_codec_realtek 55704 1 ghash_clmulni_intel 13259 0 aesni_intel 55624 0 aes_x86_64 17131 1 aesni_intel snd_hda_codec_hdmi 41117 1 x_tables 34059 13 ip6table_filter,xt_hl,ip_tables,xt_tcpudp,xt_limit,xt_conntrack,xt_LOG,iptable_filter,ip6t_rt,ipt_REJECT,ip6_tables,xt_addrtype,ip6t_REJECT lrw 13257 1 aesni_intel snd_hda_intel 48171 5 gf128mul 14951 1 lrw glue_helper 13990 1 aesni_intel ablk_helper 13597 1 aesni_intel joydev 17377 0 cryptd 20329 3 ghash_clmulni_intel,aesni_intel,ablk_helper snd_hda_codec 188738 3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel arc4 12608 2 snd_hwdep 13602 1 snd_hda_codec rt2800pci 18690 0 snd_pcm 102033 3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel radeon 1402449 3 rt2800lib 79963 1 rt2800pci btusb 28267 0 rt2x00pci 13287 1 rt2800pci rt2x00mmio 13603 1 rt2800pci snd_page_alloc 18710 2 snd_pcm,snd_hda_intel rt2x00lib 55238 4 rt2x00pci,rt2800lib,rt2800pci,rt2x00mmio snd_seq_midi 13324 0 mac80211 596969 3 rt2x00lib,rt2x00pci,rt2800lib snd_seq_midi_event 14899 1 snd_seq_midi ttm 83995 1 radeon snd_rawmidi 30095 1 snd_seq_midi cfg80211 479757 2 mac80211,rt2x00lib drm_kms_helper 52651 1 radeon snd_seq 61560 2 snd_seq_midi_event,snd_seq_midi bluetooth 371880 12 bnep,btusb,rfcomm microcode 23518 0 eeprom_93cx6 13344 1 rt2800pci snd_seq_device 14497 3 snd_seq,snd_rawmidi,snd_seq_midi crc_ccitt 12707 1 rt2800lib snd_timer 29433 2 snd_pcm,snd_seq snd 69141 21 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi psmouse 97626 0 drm 296739 5 ttm,drm_kms_helper,radeon k10temp 13126 0 soundcore 12680 1 snd serio_raw 13413 0 i2c_algo_bit 13413 1 radeon i2c_piix4 22106 0 video 19318 0 mac_hid 13205 0 lp 17759 0 parport 42299 3 lp,ppdev,parport_pc hid_generic 12548 0 usbhid 53014 0 hid 105818 2 hid_generic,usbhid pata_acpi 13038 0 usb_storage 62062 1 r8169 67341 0 sdhci_pci 18985 0 sdhci 42630 1 sdhci_pci mii 13934 1 r8169 pata_atiixp 13242 0 ohci_pci 13561 0 ahci 25819 2 libahci 31898 1 ahci Someone can help me?

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  • The Internet of Things & Commerce: Part 2 -- Interview with Brian Celenza, Commerce Innovation Strategist

    - by Katrina Gosek, Director | Commerce Product Strategy-Oracle
    Internet of Things & Commerce Series: Part 2 (of 3) Welcome back to the second installation of my three part series on the Internet of Things & Commerce. A few weeks ago, I wrote “The Next 7,000 Days” about how we’ve become embedded in a digital architecture in the last 7,000 days since the birth of the internet – an architecture that everyday ties the massive expanse of the internet evermore closely with our physical lives. This blog series explores how this new blend of virtual and material will change how we shop and how businesses sell. Now enjoy reading my interview with Brian Celenza, one of the chief strategists in our Oracle Commerce innovation group. He comments on the past, present, and future of the how the growing Internet of Things relates and will relate to the buying and selling of goods on and offline. -------------------------------------------- QUESTION: You probably have one of the coolest jobs on our team, Brian – and frankly, one of the coolest jobs in our industry. As part of the innovation team for Oracle Commerce, you’re regularly working on bold features and groundbreaking commerce-focused experiences for our vision demos. As you look back over the past couple of years, what is the biggest trend (or trends) you’ve seen in digital commerce that started to bring us closer to this idea of what people are calling an “Internet of Things”? Brian: Well as you look back over the last couple of years, the speed at which change in our industry has moved looks like one of those blurred movement photos – you know the ones where the landscape blurs because the observer is moving so quickly your eye focus can’t keep up. But one thing that is absolutely clear is that the biggest catalyst for that speed of change – especially over the last three years – has been mobile. Mobile technology changed everything. Over the last three years the entire thought process of how to sell on (and offline) has shifted because of mobile technology advances. Particularly for eCommerce professionals who have started to move past the notion of “channels” for selling goods to this notion of “Mobile First”… then the Web site. Or more accurately, that everything – smartphones, web, store, tablet – is just one channel or has to act like one singular access point to the same product catalog, information and content. The most innovative eCommerce professionals realized some time ago that it’s not ideal to build an eCommerce Web site and then build everything on top of or off of it. Rather, they want to build an eCommerce API and then integrate it will all other systems. To accomplish this, they are leveraging all the latest mobile technologies or possibilities mobile technology has opened up: 4G and LTE, GPS, bluetooth, touch screens, apps, html5… How has this all started to come together for shopping experiences on and offline? Well to give you a personal example, I remember visiting an Apple store a few years ago and being amazed that I didn’t have to wait in line because a store associate knew everything about me from my ID – right there on the sales floor – and could check me out anywhere. Then just a few months later (when like any good addict) I went back to get the latest and greatest new gadget, I felt like I was stealing it because I could check myself out with my smartphone. I didn’t even need to see a sales associate OR go to a cash register. Amazing. And since then, all sort sorts of companies across all different types of industries – from food service to apparel –  are starting to see mobile payments in the billions of dollars now thanks not only to the convenience factor but to smart loyalty rewards programs as well. These are just some really simple current examples that come to mind. So many different things have happened in the last couple of years, it’s hard to really absorb all of the quickly – because as soon as you do, everything changes again! Just like that blurry speed photo image. For eCommerce, however, this type of new environment underscores the importance of building an eCommerce API – a platform that has services you can tap in to and build on as the landscape changes at a fever pitch. It’s a mobile first perspective. A web service perspective – particularly if you are thinking of how to engage customers across digital and physical spaces. —— QUESTION: Thanks for bringing us into the present – some really great examples you gave there to put things into perspective. So what do you see as the biggest trend right now around the “Internet of Things” – and what’s coming next few years? Brian: Honestly, even sitting where I am in the innovation group – it’s hard to look out even 12 months because, well, I don’t even think we’ve fully caught up with what is possible now. But I can definitely say that in the last 12 months and in the coming 12 months, in the technology and eCommerce world it’s all about iBeacons. iBeacons are awesome tools we have right now to tie together physical and digital shopping experiences. They know exactly where you are as a shopper and can communicate that to businesses. Currently there seem to be two camps of thought around iBeacons. First, many people are thinking of them like an “indoor GPS”, which to be fair they literally are. The use case this first camp envisions for iBeacons is primarily for advertising and marketing. So they use iBeacons to push location-based promotions to customers if they are close to a store or in a store. You may have seen these types of mobile promotions start to pop up occasionally on your smart phone as you pass by a store you’ve bought from in the past. That’s the work of iBeacons. But in my humble opinion, these promotions probably come too early in the customer journey and although they may be well timed and work to “convert” in some cases, I imagine in most they are just eroding customer trust because they are kind of a “one-size-fits-all” solution rather than one that is taking into account what exactly the customer might be looking for in that particular moment. Maybe they just want more information and a promotion is way too soon for that type of customer. The second camp is more in line with where my thinking falls. In this case, businesses take a more sensitive approach with iBeacons to customers’ needs. Instead of throwing out a “one-size-fits-all” to any passer by with iBeacons, the use case is more around looking at the physical proximity of a customer as an opportunity to provide a service: show expert reviews on a product they may be looking at in a particular aisle of a store, offer the opportunity to compare prices (and then offer a promotion), signal an in-store associate if a customer has been in the store for more than 10 minutes in one place. These are all less intrusive more value-driven uses of iBeacons. And they are more about building customer trust through service. To take this example a bit further into the future realm of “Big Data” and “Internet of Things” businesses could actually use the Oracle Commerce Platform and iBeacons to “silently” track customer movement w/in the store to provide higher quality service. And this doesn’t have to be creepy or intrusive. Simply if a customer has been in a particular department or aisle for more than a 5 or 10 minutes, an in-store associate could come over an offer some assistance already knowing customer preferences from their online profile and maybe even seeing the items in a shopping cart they started at home. None of this has to be revealed to the customer, but it certainly could boost the level of service an in-store sales associate could provide. Or, in another futuristic example, stores could use the digital footprint of the physical store transmitted by iBeacons to generate heat maps of the store that could be tracked over time. Imagine how much you could find out about which parts of the store are more busy during certain parts of the day or seasons. This could completely revolutionize how physical merchandising is deployed or where certain high value / new items are placed. And / or this use of iBeacons could also help businesses figure out if customers are getting held up in certain parts of the store during busy days like Black Friday. If long lines are causing customers to bounce from a physical store and leave those holiday gifts behind, maybe having employees with mobile check as an option could remove the cash register bottleneck. But going to back to my original statement, it’s all still very early in the story for iBeacons. The hardware manufacturers are still very new and there is still not one clear standard.  Honestly, it all goes back to building and maintaining an extensible and flexible platform for anywhere engagement. What you’re building today should allow you to rapidly take advantage of whatever unimaginable use cases wait around the corner. ------------------------------------------------------ I hope you enjoyed the brief interview with Brian. It’s really awesome to have such smart and innovation-minded individuals on our Oracle Commerce innovation team. Please join me again in a few weeks for Part 3 of this series where I interview one of the product managers on our team about how the blending of digital and in-store selling in influencing our product development and vision.

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Oracle Flashback Technologies - Overview

    - by Sridhar_R-Oracle
    Oracle Flashback Technologies - IntroductionIn his May 29th 2014 blog, my colleague Joe Meeks introduced Oracle Maximum Availability Architecture (MAA) and discussed both planned and unplanned outages. Let’s take a closer look at unplanned outages. These can be caused by physical failures (e.g., server, storage, network, file deletion, physical corruption, site failures) or by logical failures – cases where all components and files are physically available, but data is incorrect or corrupt. These logical failures are usually caused by human errors or application logic errors. This blog series focuses on these logical errors – what causes them and how to address and recover from them using Oracle Database Flashback. In this introductory blog post, I’ll provide an overview of the Oracle Database Flashback technologies and will discuss the features in detail in future blog posts. Let’s get started. We are all human beings (unless a machine is reading this), and making mistakes is a part of what we do…often what we do best!  We “fat finger”, we spill drinks on keyboards, unplug the wrong cables, etc.  In addition, many of us, in our lives as DBAs or developers, must have observed, caused, or corrected one or more of the following unpleasant events: Accidentally updated a table with wrong values !! Performed a batch update that went wrong - due to logical errors in the code !! Dropped a table !! How do DBAs typically recover from these types of errors? First, data needs to be restored and recovered to the point-in-time when the error occurred (incomplete or point-in-time recovery).  Moreover, depending on the type of fault, it’s possible that some services – or even the entire database – would have to be taken down during the recovery process.Apart from error conditions, there are other questions that need to be addressed as part of the investigation. For example, what did the data look like in the morning, prior to the error? What were the various changes to the row(s) between two timestamps? Who performed the transaction and how can it be reversed?  Oracle Database includes built-in Flashback technologies, with features that address these challenges and questions, and enable you to perform faster, easier, and convenient recovery from logical corruptions. HistoryFlashback Query, the first Flashback Technology, was introduced in Oracle 9i. It provides a simple, powerful and completely non-disruptive mechanism for data verification and recovery from logical errors, and enables users to view the state of data at a previous point in time.Flashback Technologies were further enhanced in Oracle 10g, to provide fast, easy recovery at the database, table, row, and even at a transaction level.Oracle Database 11g introduced an innovative method to manage and query long-term historical data with Flashback Data Archive. The 11g release also introduced Flashback Transaction, which provides an easy, one-step operation to back out a transaction. Oracle Database versions 11.2.0.2 and beyond further enhanced the performance of these features. Note that all the features listed here work without requiring any kind of restore operation.In addition, Flashback features are fully supported with the new multi-tenant capabilities introduced with Oracle Database 12c, Flashback Features Oracle Flashback Database enables point-in-time-recovery of the entire database without requiring a traditional restore and recovery operation. It rewinds the entire database to a specified point in time in the past by undoing all the changes that were made since that time.Oracle Flashback Table enables an entire table or a set of tables to be recovered to a point in time in the past.Oracle Flashback Drop enables accidentally dropped tables and all dependent objects to be restored.Oracle Flashback Query enables data to be viewed at a point-in-time in the past. This feature can be used to view and reconstruct data that was lost due to unintentional change(s) or deletion(s). This feature can also be used to build self-service error correction into applications, empowering end-users to undo and correct their errors.Oracle Flashback Version Query offers the ability to query the historical changes to data between two points in time or system change numbers (SCN) Oracle Flashback Transaction Query enables changes to be examined at the transaction level. This capability can be used to diagnose problems, perform analysis, audit transactions, and even revert the transaction by undoing SQLOracle Flashback Transaction is a procedure used to back-out a transaction and its dependent transactions.Flashback technologies eliminate the need for a traditional restore and recovery process to fix logical corruptions or make enquiries. Using these technologies, you can recover from the error in the same amount of time it took to generate the error. All the Flashback features can be accessed either via SQL command line (or) via Enterprise Manager.  Most of the Flashback technologies depend on the available UNDO to retrieve older data. The following table describes the various Flashback technologies: their purpose, dependencies and situations where each individual technology can be used.   Example Syntax Error investigation related:The purpose is to investigate what went wrong and what the values were at certain points in timeFlashback Queries  ( select .. as of SCN | Timestamp )   - Helps to see the value of a row/set of rows at a point in timeFlashback Version Queries  ( select .. versions between SCN | Timestamp and SCN | Timestamp)  - Helps determine how the value evolved between certain SCNs or between timestamps Flashback Transaction Queries (select .. XID=)   - Helps to understand how the transaction caused the changes.Error correction related:The purpose is to fix the error and correct the problems,Flashback Table  (flashback table .. to SCN | Timestamp)  - To rewind the table to a particular timestamp or SCN to reverse unwanted updates Flashback Drop (flashback table ..  to before drop )  - To undrop or undelete a table Flashback Database (flashback database to SCN  | Restore Point )  - This is the rewind button for Oracle databases. You can revert the entire database to a particular point in time. It is a fast way to perform a PITR (point-in-time recovery). Flashback Transaction (DBMS_FLASHBACK.TRANSACTION_BACKOUT(XID..))  - To reverse a transaction and its related transactions Advanced use cases Flashback technology is integrated into Oracle Recovery Manager (RMAN) and Oracle Data Guard. So, apart from the basic use cases mentioned above, the following use cases are addressed using Oracle Flashback. Block Media recovery by RMAN - to perform block level recovery Snapshot Standby - where the standby is temporarily converted to a read/write environment for testing, backup, or migration purposes Re-instate old primary in a Data Guard environment – this avoids the need to restore an old backup and perform a recovery to make it a new standby. Guaranteed Restore Points - to bring back the entire database to an older point-in-time in a guaranteed way. and so on..I hope this introductory overview helps you understand how Flashback features can be used to investigate and recover from logical errors.  As mentioned earlier, I will take a deeper-dive into to some of the critical Flashback features in my upcoming blogs and address common use cases.

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  • The 20 Most Important Keyboard Shortcuts For Windows PCs

    - by Chris Hoffman
    Keyboard shortcuts are practically essential for using any type of PC. They’ll speed up almost everything you do. But long lists of keyboard shortcuts can quickly become overwhelming if you’re just getting started. This list will cover the most useful keyboard shortcuts that every Windows user should know. If you haven’t used keyboard shortcuts much, these will show you just how useful keyboard shortcuts can be. Windows Key + Search The Windows key is particularly important on Windows 8 — especially before Windows 8.1 — because it allows you to quickly return to the Start screen. On Windows 7, it opens the Start menu. Either way, you can start typing immediately after you press the Windows key to search for programs, settings, and files. For example, if you want to launch Firefox, you can press the Windows key, start typing the word Firefox, and press Enter when the Firefox shortcut appears. It’s a quick way to launch programs, open files, and locate Control Panel options without even touching your mouse and without digging through a cluttered Start menu. You can also use the arrow keys to select the shortcut you want to launch before pressing Enter. Copy, Cut, Paste Copy, Cut, and Paste are extremely important keyboard shortcuts for text-editing. If you do any typing on your computer, you probably use them. These options can be accessed using the mouse, either by right-clicking on selected text or opening the application’s Edit menu, but this is the slowest way to do it. After selecting some text, press Ctrl+C to copy it or Ctrl+X to cut it. Position the cursor where you want the text and use Ctrl+V to paste it. These shortcuts can save you a huge amount of time over using the mouse. Search the Current Page or File To quickly perform a search in the current application — whether you’re in a web browser, PDF viewer, document editor, or almost any other type of application — press Ctrl+F. The application’s search (or “Find”) feature will pop up, and you can instantly start typing a phrase you want to search for. You can generally press Enter to  go to the next appearance of the word or phrase in the document, quickly searching through it for what you’re interested in. Switch Between Applications and Tabs Rather than clicking buttons on your taskbar, Alt+Tab is a very quick way to switch between running applications. Windows orders the list of open windows by the order you accessed them, so if you’re only using two different applications, you can just press Alt+Tab to quickly switch between them. If switching between more than two windows, you’ll have to hold the Alt key and press Tab repeatedly to toggle through the list of open windows. If you miss the window you want, you can always press Alt+Shift+Tab to move through the list in reverse. To move between tabs in an application — such as the browser tabs in your web browser — press Ctrl+Tab. Ctrl+Shift+Tab will move through tabs in reverse. Quickly Print If you’re the kind of person who still prints things, you can quickly open the print window by pressing Ctrl+P. This can be faster than hunting down the Print option in every program you want to print something from. Basic Browser Shortcuts Web browser shortcuts can save you tons of time, too. Ctrl+T is a very useful one, as it will open a new tab with the address bar focused, so you can quickly press Ctrl +T, type a search phrase or web address, and press Enter to go there. To go back or forward while browsing, hold the Ctrl key and press the left or right arrow keys. If you’d just like to focus your web browser’s address bar so you can type a new web address or search without opening a new tab, press Ctrl + L. You can then start typing something and press Enter. Close Tabs and Windows To quickly close the current application, press Alt+F4. This works on the desktop and even in new Windows 8-style applications. To quickly close the current browser tab or document, press Ctrl+W. This will often close the current window if there are no other tabs open. Lock Your Computer When you’re done using your computer and want to step away, you may want to lock it. People won’t be able to log in and access your desktop unless they know your password. You can do this from the Start menu or Start screen, but the fastest way to lock your screen is by quickly pressing Windows Key + L before you get up. Access the Task Manager Ctrl+Alt+Delete will take you to a screen that allows you to quickly launch the Task Manager or perform other operations, such as signing out. This is particularly useful because if can be used to recover from situations where your computer doesn’t appear responsive or isn’t accepting input. For example, if a full-screen game becomes unresponsive, Ctrl+Alt+Delete will often allow you to escape from it and end it via the Task Manager. Windows 8 Shortcuts On Windows 8 PCs, there are other very important keyboard shortcuts. Windows Key + C will open your Charms bar, while Windows Key + Tab will open the new App Switcher. These keyboard shortcuts will allow you to avoid the hot corners, which can be tedious to use with a mouse. On the desktop side, Windows Key + D will take you back to the desktop from anywhere. Windows Key + X will open a special “power user menu” that gives you quick access to options that are hidden in the new Windows 8 interface, including Shut Down, Restart, and Control Panel. If you’re interested in learning more keyboard shortcuts, be sure to check our longer lists of 47 keyboard shortcuts that work in all web browsers and 42+ keyboard shortcuts to speed up text-editing. Image Credit: Jeroen Bennink on Flickr     

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Is HR/Recruitment Really Ready For Innovative Candidates

    - by david.talamelli
    Before I begin this blog post, I want to acknowledge that there are some great HR/Recruitment people out there who are innovative and are leading the way in using new means to successfully attract and connect with talented people. For those of you who fit in this category, please keep thinking outside the square - just because what you do may not be the norm doesn't mean it is bad. Ok, with that acknowledgment out of the way - Earlier this morning (I started this post Friday morning) I came across this online profile via a tweet from Philip Tusing I love the information that Jason has put on his web-pages. From his work Jason clearly demonstrates not only his skills/experience but also I love how he relates his experience and shows how it will help an employer and what the value add of having him on your team is. Looking at Jason's profile makes me think though, is HR/Recruitment in general terms ready to deal with innovative candidates. Sure most Recruiters are online in some form or another, but how many actually have a process that is flexible enough to deal with someone who may not fit into your processes. Is your company's recruitment practice proactive enough to find Jason's web-pages? I am not sure what he is doing in terms of a job search, but if he is not mailing a resume or replying to ads on a Job Board - hopefully Jason comes up on some of the candidate searching you are doing. Once you find this information, would the information Jason provides fit nicely into your Applicant Tracking System or your Database? If not, how much of the intangible information are you losing and potentially not passing on to a Hiring Manager. I think what has worked in the past will not necessarily work in the future. Candidates want to work somewhere they will be challenged and learn and grow. If your HR/Recruitment team displays processes that take don't necessarily convey this message, this potentially could turn people away who were once interested in your company. For example (and I have to admit I still do some of these things myself), once calling up and having a talk to a candidate a company may say: 1) HR Question: Send me in a copy of your resume - Candidate Reply - you actually already have my resume, the web-page is http:// 2) HR Question:Come in for a chat so we can get to know you - Candidate Reply - if this is the basis of a meeting, you already know me and my thoughts by looking at my online links (blog, portfolio, homepage, etc...) These questions if not handled properly could potentially turn a candidate from being interested in your company to not being interested in your company. It potentially could demonstrate that your company is not social media savvy or maybe give the impression of not really being all that innovative. A candidate may think, if this company isn't able to take information I have provided in the public forum and use it, is it really a company I want to work for? I think when liaising with candidates a company should utilise the information the person has provided in the public domain. A candidate may inadvertantly give you answers to many of the questions you are seeking on their online presence and save everyone time instead of having to fill out forms or paperwork. If you build this into your conversations with your candidates it becomes a much more individualised service you are providing and really demonstrates to a candidate you are thinking of them as an individual. Yes I know we need to have processes in place and I am not saying don't work to those processes, but don't let process take away a candidates individuality. Don't let your process inadvertently scare away the top candidates that you may want in your company. This article was originally posted on David Talamelli's Blog - David's Journal on Tap

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  • Expression Studio 4 - without SketchFlow&hellip;

    - by mbcrump
    is kinda like an explosion with no “Ka-Boom”… I was excited to hear the news yesterday at Microsoft Teched that Expression Studio 4 had officially launched. MSDN subscribers could log in and download the full release. So, I logged into my MSDN account and started downloading Expression Studio 4 Premium thinking that I was only minutes away from trying out SketchFlow 4. To my dismay, I launched Blend 4 and noticed it did not say SketchFlow on the splash screen. So, I went to New Project and the template was not available. After some digging around on the net, I learned my premium MSDN subscription did not include SketchFlow and I would need to purchase the Ultimate Edition. Below is a excerpt directly from Microsoft: Q: What products are included in the Microsoft Expression Studio 4 Ultimate? A: Expression Studio 4 Ultimate is comprised of 4 products, Expression Web 4, Microsoft Expression Blend® 4 + SketchFlow, Expression Encoder 4 Pro and Expression Design 4. Expression Blend 4 includes SketchFlow in Expression Studio 4 Ultimate product only. Q: What products are included in the Microsoft Expression Studio 4 Premium? A: Expression Studio 4 Premium is comprised of 4 products, Expression Web 4, Microsoft Expression Blend 4, Expression Encoder 4 and Expression Design 4. Expression Studio 4 Premium is not available for retail purchase. Q: What products are included in the Microsoft Expression Studio 4 Web Professional? A: Expression Studio 4 Web Professional is comprised of 3 products, Expression Web 4, Expression Encoder 4 and Expression Design 4. As you can see, we got screwed on this deal and plenty of people are complaining: Kiran Says: 6.07.2010 at 5:07 PM No SketchFlow for Expression Studio 4 Premium? What a bumper for Microsoft Partners!! Martin Says: 6.07.2010 at 6:18 PM Why does Expression Professional Subscription not include upgrades and new releases of Expression Studio. Good question hey. I bought my subscription 5 days ago thinking I would get what i purchased but no Expression upgrades or new releases for me, what a waste of money. I think I am not the only long term user of this software that feels disgruntled. Sorry john just had to tell someone. shaggygi Says: 6.07.2010 at 7:31 PM SketchFlow NOT included in Studio 4? WTF! I repeat.... WT...Freaking.... F! This is totally unacceptable. My development team purchased VS 2010 Premium w/ MSDN with the impression by Adam Kinney, Scott Guthrie, etc. that this would be included in the Premium package or some sort of free upgrade. I understand this is a Marketing thing, but come on! I believe, at very least, this should have been explained in detail before this release. John Papa... as a rep to give feedback to the team... Please please and please.... tell powers-at-be to fix this problem. Sorry for the rant. Besides this issue, I believe it is a very good product:) Thanks Vaclav Elias Says: 6.08.2010 at 4:30 AM Well, I am also not happy that SketchFlow is only for the chosen ones :-) It is very nice product. Actually, kind of foundation for web development so they could really support any MSDN subscribers.. :-( I am hoping that Microsoft will make this right for all of us with MSDN premier subscriptions. In the meantime,  you can check out the 5 day training series available here.

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  • Call Webservices&hellip;Maybe!?

    - by MOSSLover
    So I have been doing preliminary work for my iOS talk for a while, but did not get into the meat of the project until recently.  One day I envision my talk uploading pictures from a camera on an iPhone or iPad into SharePoint and telling people how I did it.  As you know with my Silverlight talk and any new technology, building new talks with new technologies always ends up with some pain points that you must jump over just to grab data.  So step 1 always starts out with how do we even access a webservice using the new technology. I started out watching every single SPC video available on oAuth and Rest Webservices in SharePoint 2013.  I also sent an email to Eric Shupps about some REST and 2013 examples.  The videos further confused me, because all the videos were on SharePoint hosted apps (provider and autohosted).  I did not want to create a SharePoint hosted app, but instead a mobile app outside of the SharePoint context altogether.  Nick Swan sent me his code and it was great for a starting point on how the JSON calls would look like on iOS, but I was still missing a piece.  Nick does a great job on showing how to use the REST/JSON calls in a non-MS tech, however his presentation uses the SharePoint context and can grab the SPAppToken.  At this point I had to ask the question how do you grab the SAML token outside of SharePoint 2013 in iOS using Objective-C?  After reading all the MSDN documentation, some documentation on Restkit and Objective-C/oAuth calls, and some SharePoint 2013 blog post my head was swimming.  I was dreaming about REST and iOS in SharePoint 2013.  SAML tokens were taunting me.  I was nowhere near understanding 2013. I started talking to my friend, Pedro Jimenez, who is also playing with Objective-C and went to SPC.  He found me a couple good MSDN posts with REST/JSON calls that basically showed the accessToken was all I needed (at this point I was still thinking iOS needed to be a provider hosted app which is wrong).  So then again I had to ask the SAML token question…How do you get a SAML token outside of SharePoint without the TokenHelper class? So then I started talking to people and thinking why do I need to completely avoid TokenHelper…The solution in concept is basically create a webservice in Azure wrapped into a Provider Hosted App in SharePoint.  Wictor Wilen created a helper webservice in the following blog post: http://www.wictorwilen.se/Post/How-to-do-active-authentication-to-Office-365-and-SharePoint-Online.aspx. So now I have to basically stand up the webservice, the SharePoint app wrapper, and then use Restkit to call the first webservice to grab the token and then the second webservice to pass in the token and grab some SharePoint data.  What this means is that you can no longer just pass credentials into SharePoint webservices and get data back.  You have to pass in a SAML token with every single webservice call to SharePoint.  The theory is that this token is associated with the permissions the app can handle (read, write, whatever).  It seems like a ton of pain and a lot of work, but this is step 1 in my crusade to pull some piece of data into iOS from SharePoint and show people how to do it themselves.  In the upcoming months hopefully I can get halfway to my end goal. Technorati Tags: SharePoint 2013,REST,oAuth,Objective-C,iOS

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  • What Banks Can Learn From An English Teacher’s Advice

    - by Gaurav H
    The earliest definitions I learnt at school pertained to nouns and verbs. Nouns, my teacher said, indicated names of people, things and places. Verbs, the stern lady said, are “action words”. They indicated motion.  The idea for this blog filtered in when I applied these definitions to the entity I most often deal with for my personal financial needs, and think about or relate to from a professional standpoint: ‘a bank’. Noun? It certainly is. At least that’s how I’d had it figured in my head. It used to be a place I visited to get my financial business done. It is the name of an entity I have a business relationship with. But, taking a closer look at how ‘the bank’ has evolved recently makes me wonder. Is it not after all acquiring some shades of a verb? For one, it’s in motion if I consider my mobile device with its financial apps. For another, it’s in ‘quasi-action’ if I consider a highly interactive virtual bank. The point I’m driving at is not semantic. But the words we use and the way we use them are revealing, and can offer tremendous insights into our existing mindsets. I think the same applies to businesses. Banks that first began examining and deconstructing their cherished ‘definitions’ or business models (nouns) were the earliest to adapt, change, and reinvent (verbs). They were able to waltz past disintermediation threats. Though rooted in a ‘brick and mortar’ heritage, their thinking and infrastructure were flexible enough for the digital era. While their physical premises imposed restrictions—opening hours, transaction hours, appointments, waiting time, overcrowding, processing time, clearing time, etc,—their thinking did not. They innovated. Across traditional and new-era channels, they easily slipped in customer services of a differentiated kind: spot loans, deposits with idle account balances, convenient mortgages with multiple liens or collateral, and instant payment options.I believe the most successful banks are those that fit into the rhythm of their customers’ lives rather than forcing their customers to fit into theirs. It was true for banks that existed before the Internet era; it’s true for banks now. I look no further than UBANK, JIBUN and HBOS Germany to make my point. They are resounding successes because they are not trapped in their own definitions of ‘a bank’. They walk with their customers, rather than waiting for their clients to walk-in for services.Back to my English teacher. She once advised me to use more verbs in my composition. Readers relate better to “action” she said. Banks too can profit from her advice. To succeed, they need to interact more. And remain flexible enough to interact with their customers. Sonny Singh is Senior Vice President  and General Manager of the Oracle Financial Services Global Business Unit. He can be reached at sonny.singh AT oracle.com or on twitter @sonnyhsingh

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