Search Results

Search found 3617 results on 145 pages for 'physical wear'.

Page 70/145 | < Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >

• 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.

  Read the article

• SQL University: What and why of database refactoring

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Tools of the trade This is a second part of the series and in it we’ll take a look at what database refactoring is and why do it. Why refactor a database To know why refactor we first have to know what refactoring actually is. Code refactoring is a process where we change module internals in a way that does not change that module’s input/output behavior. For successful refactoring there is one crucial thing we absolutely must have: Tests. Automated unit tests are the only guarantee we have that we haven’t broken the input/output behavior before refactoring. If you haven’t go back ad read my post on the matter. Then start writing them. Next thing you need is a code module. Those are views, UDFs and stored procedures. By having direct table access we can kiss fast and sweet refactoring good bye. One more point to have a database abstraction layer. And no, ORM’s don’t fall into that category. But also know that refactoring is NOT adding new functionality to your code. Many have fallen into this trap. Don’t be one of them and resist the lure of the dark side. And it’s a strong lure. We developers in general love to add new stuff to our code, but hate fixing our own mistakes or changing existing code for no apparent reason. To be a good refactorer one needs discipline and focus. Now we know that refactoring is all about changing inner workings of existing code. This can be due to performance optimizations, changing internal code workflows or some other reason. This is a typical black box scenario to the outside world. If we upgrade the car engine it still has to drive on the road (preferably faster) and not fly (no matter how cool that would be). Also be aware that white box tests will break when we refactor. What to refactor in a database Refactoring databases doesn’t happen that often but when it does it can include a lot of stuff. Let us look at a few common cases. Adding or removing database schema objects Adding, removing or changing table columns in any way, adding constraints, keys, etc… All of these can be counted as internal changes not visible to the data consumer. But each of these carries a potential input/output behavior change. Dropping a column can result in views not working anymore or stored procedure logic crashing. Adding a unique constraint shows duplicated data that shouldn’t exist. Foreign keys break a truncate table command executed from an application that runs once a month. All these scenarios are very real and can happen. With the proper database abstraction layer fully covered with black box tests we can make sure something like that does not happen (hopefully at all). Changing physical structures Physical structures include heaps, indexes and partitions. We can pretty much add or remove those without changing the data returned by the database. But the performance can be affected. So here we use our performance tests. We do have them, right? Just by adding a single index we can achieve orders of magnitude performance improvement. Won’t that make users happy? But what if that index causes our write operations to crawl to a stop. again we have to test this. There are a lot of things to think about and have tests for. Without tests we can’t do successful refactoring! Fixing bad code We all have some bad code in our systems. We usually refer to that code as code smell as they violate good coding practices. Examples of such code smells are SQL injection, use of SELECT *, scalar UDFs or cursors, etc… Each of those is huge code smell and can result in major code changes. Take SELECT * from example. If we remove a column from a table the client using that SELECT * statement won’t have a clue about that until it runs. Then it will gracefully crash and burn. Not to mention the widely unknown SELECT * view refresh problem that Tomas LaRock (@SQLRockstar on Twitter) and Colin Stasiuk (@BenchmarkIT on Twitter) talk about in detail. Go read about it, it’s informative. Refactoring this includes replacing the * with column names and most likely change to application using the database. Breaking apart huge stored procedures Have you ever seen seen a stored procedure that was 2000 lines long? I have. It’s not pretty. It hurts the eyes and sucks the will to live the next 10 minutes. They are a maintenance nightmare and turn into things no one dares to touch. I’m willing to bet that 100% of time they don’t have a single test on them. Large stored procedures (and functions) are a clear sign that they contain business logic. General opinion on good database coding practices says that business logic has no business in the database. That’s the applications part. Refactoring such behemoths requires writing lots of edge case tests for the stored procedure input/output behavior and then start to refactor it. First we split the logic inside into smaller parts like new stored procedures and UDFs. Those then get called from the master stored procedure. Once we’ve successfully modularized the database code it’s best to transfer that logic into the applications consuming it. This only leaves the stored procedure with common data manipulation logic. Of course this isn’t always possible so having a plethora of performance and behavior unit tests is absolutely necessary to confirm we’ve actually improved the codebase in some way.   Refactoring is not a popular chore amongst developers or managers. The former don’t like fixing old code, the latter can’t see the financial benefit. Remember how we talked about being lousy at estimating future costs in the previous post? But there comes a time when it must be done. Hopefully I’ve given you some ideas how to get started. In the last post of the series we’ll take a look at the tools to use and an example of testing and refactoring.

  Read the article

• Top ten things that don't make sense in The Walking Dead

  - by iamjames

  For those of you that don't know, The Walking Dead is a popular American TV show on AMC about a group of people trying to survive in a zombie-filled world.Here's the top ten eleven things that don't make sense on the show (and have never been explained) 1)  They never visit stores.  No Walmarts, Kmarts, Targets, shopping malls, pawn shops, gas stations, etc.  You'd think that would be the first place you'd visit for supplies, but they never have.  Not once.  There was a tiny corner store they visited in a small town, and while many products were already gone they did find several useful items.  2)  They never raid houses.  Why not?  One would imagine that they would want to search houses for useful items, but they don't.3)  They don't use 2 way radios.  Modern 2-way radios have a 36-mile range.  That's probably best possible range, but even if the range is only 10% of that, 3.6 miles, that's still more than enough for most situations, for the occasional "hey zombies attacking can you give me a hand?" or "there's zombies walking by stay inside until they leave" or "remember to pick up milk at the store love mom".  And yes they would need batteries or recharging, but they have been using gas-powered generators on the show and I'm sure a car charger would work.4)  They use gas-guzzling vehicles.  Every vehicle they have is from the 80s or 90s except for the new Kia SUV there for product placement.  Why?  They should all be driving new small SUVs or hybrids.  Visit a dealership and steal more fuel-efficient vehicles, because while the Walmart's might be empty from people raiding them for supplies, I'm sure most people weren't thinking "Gee, I should go car shopping" when the infection hit5)  They drive a motorcycle.  Seriously?  Let's find the least protective vehicle and drive that.  And while motorcycles get reasonable gas mileage, 5 people in a SUV gets better gas mileage per person than 5 people all driving motorcycles so it doesn't make economical sense either.6)  They drive loud vehicles.  The motorcycle used is commonly referred to as a chopper and is about as loud as a motorcycle can get.  The zombies are attracted to loud noise, so wouldn't it make more sense to drive vehicles that makes less sound?  Because as soon as you stop the bike and get off you're surrounded by zombies that heard you coming.  And it's not just the bike, the ~1980s Chevy SUV in the show is also very loud.7)  They never run out of food.  Seems like that would be a almost daily struggle, keeping enough food available for about a dozen people, yet I've never seen them visit a grocery store or local convenience store to stock up.8)  They don't carry swords, machetes, clubs, etc.  Let's face it, biting is not a very effective means of attack.  It's good for animals because they have fangs and little else, but humans have been finding better ways of killing each other since forever.  So why doesn't everyone on the show carry a sword or machete or at least a baseball bat?  Anything is better than wasting valuable bullets all the time.  Sure, dozen zombies approaching?  Shoot them.  One zombie approaching?  Save the bullet, cut off it's head.  9)  They do not wear protective clothing.  Human teeth are not exactly the sharpest teeth in the animal kingdom.  The leather shoes your dog ripped to shreds within minutes would probably take you days to bite through.  So why do they walk around half-naked?  Yes I know it's hot in Atlanta, but you'd think they'd at least have some tough leather coats or something for protection.  Maybe put a few small vent holes in the fabric if it's really hot.  Or better:  make your own chainmail.  Chainmail was used for thousands of years for protection from swords and is still used by scuba divers for protection from sharks.  If swords and sharks can't puncture it, human teeth don't stand a chance.  10)  They don't build barricades or dig trenches around properties.  In Season 2 they stayed at a farm in the middle of no where.  While being far away from people is a great way to stay far away from zombies, it would still make sense to build some sort of defenses.  Hordes of zombies would knock down almost any fence, but what about a trench or moat?  Maybe something not too wide so it can be jumped over easily but a zombie would fall into because I haven't seen too many jumping zombies on the show.  11)  They don't live in a mall or tall office building.  A mall would be perfect.  They have large security gates designed to keep even hundreds of people from breaking in and offer lots of supplies and food.  They're usually hundreds of thousands of square feet and fully enclosed, one could probably live their entire life happily in a mall.  Tall office building with on-site cafeteria would be another good choice.  They also usually offer good security and office furniture could be pushed out of the windows to crush approaching zombies, and the cafeteria is usually stocked to provide food for hundreds or thousands of office workers so food wouldn't be a problem for a long time. So there you have it, eleven things that don't make sense in The Walking Dead.  Have any of your own you'd like to add or were one of these things covered in the show?  Let me know in the comments.

  Read the article

• NUMA-aware placement of communication variables

  - by Dave

  For classic NUMA-aware programming I'm typically most concerned about simple cold, capacity and compulsory misses and whether we can satisfy the miss by locally connected memory or whether we have to pull the line from its home node over the coherent interconnect -- we'd like to minimize channel contention and conserve interconnect bandwidth. That is, for this style of programming we're quite aware of where memory is homed relative to the threads that will be accessing it. Ideally, a page is collocated on the node with the thread that's expected to most frequently access the page, as simple misses on the page can be satisfied without resorting to transferring the line over the interconnect. The default "first touch" NUMA page placement policy tends to work reasonable well in this regard. When a virtual page is first accessed, the operating system will attempt to provision and map that virtual page to a physical page allocated from the node where the accessing thread is running. It's worth noting that the node-level memory interleaving granularity is usually a multiple of the page size, so we can say that a given page P resides on some node N. That is, the memory underlying a page resides on just one node. But when thinking about accesses to heavily-written communication variables we normally consider what caches the lines underlying such variables might be resident in, and in what states. We want to minimize coherence misses and cache probe activity and interconnect traffic in general. I don't usually give much thought to the location of the home NUMA node underlying such highly shared variables. On a SPARC T5440, for instance, which consists of 4 T2+ processors connected by a central coherence hub, the home node and placement of heavily accessed communication variables has very little impact on performance. The variables are frequently accessed so likely in M-state in some cache, and the location of the home node is of little consequence because a requester can use cache-to-cache transfers to get the line. Or at least that's what I thought. Recently, though, I was exploring a simple shared memory point-to-point communication model where a client writes a request into a request mailbox and then busy-waits on a response variable. It's a simple example of delegation based on message passing. The server polls the request mailbox, and having fetched a new request value, performs some operation and then writes a reply value into the response variable. As noted above, on a T5440 performance is insensitive to the placement of the communication variables -- the request and response mailbox words. But on a Sun/Oracle X4800 I noticed that was not the case and that NUMA placement of the communication variables was actually quite important. For background an X4800 system consists of 8 Intel X7560 Xeons . Each package (socket) has 8 cores with 2 contexts per core, so the system is 8x8x2. Each package is also a NUMA node and has locally attached memory. Every package has 3 point-to-point QPI links for cache coherence, and the system is configured with a twisted ladder "mobius" topology. The cache coherence fabric is glueless -- there's not central arbiter or coherence hub. The maximum distance between any two nodes is just 2 hops over the QPI links. For any given node, 3 other nodes are 1 hop distant and the remaining 4 nodes are 2 hops distant. Using a single request (client) thread and a single response (server) thread, a benchmark harness explored all permutations of NUMA placement for the two threads and the two communication variables, measuring the average round-trip-time and throughput rate between the client and server. In this benchmark the server simply acts as a simple transponder, writing the request value plus 1 back into the reply field, so there's no particular computation phase and we're only measuring communication overheads. In addition to varying the placement of communication variables over pairs of nodes, we also explored variations where both variables were placed on one page (and thus on one node) -- either on the same cache line or different cache lines -- while varying the node where the variables reside along with the placement of the threads. The key observation was that if the client and server threads were on different nodes, then the best placement of variables was to have the request variable (written by the client and read by the server) reside on the same node as the client thread, and to place the response variable (written by the server and read by the client) on the same node as the server. That is, if you have a variable that's to be written by one thread and read by another, it should be homed with the writer thread. For our simple client-server model that means using split request and response communication variables with unidirectional message flow on a given page. This can yield up to twice the throughput of less favorable placement strategies. Our X4800 uses the QPI 1.0 protocol with source-based snooping. Briefly, when node A needs to probe a cache line it fires off snoop requests to all the nodes in the system. Those recipients then forward their response not to the original requester, but to the home node H of the cache line. H waits for and collects the responses, adjudicates and resolves conflicts and ensures memory-model ordering, and then sends a definitive reply back to the original requester A. If some node B needed to transfer the line to A, it will do so by cache-to-cache transfer and let H know about the disposition of the cache line. A needs to wait for the authoritative response from H. So if a thread on node A wants to write a value to be read by a thread on node B, the latency is dependent on the distances between A, B, and H. We observe the best performance when the written-to variable is co-homed with the writer A. That is, we want H and A to be the same node, as the writer doesn't need the home to respond over the QPI link, as the writer and the home reside on the very same node. With architecturally informed placement of communication variables we eliminate at least one QPI hop from the critical path. Newer Intel processors use the QPI 1.1 coherence protocol with home-based snooping. As noted above, under source-snooping a requester broadcasts snoop requests to all nodes. Those nodes send their response to the home node of the location, which provides memory ordering, reconciles conflicts, etc., and then posts a definitive reply to the requester. In home-based snooping the snoop probe goes directly to the home node and are not broadcast. The home node can consult snoop filters -- if present -- and send out requests to retrieve the line if necessary. The 3rd party owner of the line, if any, can respond either to the home or the original requester (or even to both) according to the protocol policies. There are myriad variations that have been implemented, and unfortunately vendor terminology doesn't always agree between vendors or with the academic taxonomy papers. The key is that home-snooping enables the use of a snoop filter to reduce interconnect traffic. And while home-snooping might have a longer critical path (latency) than source-based snooping, it also may require fewer messages and less overall bandwidth. It'll be interesting to reprise these experiments on a platform with home-based snooping. While collecting data I also noticed that there are placement concerns even in the seemingly trivial case when both threads and both variables reside on a single node. Internally, the cores on each X7560 package are connected by an internal ring. (Actually there are multiple contra-rotating rings). And the last-level on-chip cache (LLC) is partitioned in banks or slices, which with each slice being associated with a core on the ring topology. A hardware hash function associates each physical address with a specific home bank. Thus we face distance and topology concerns even for intra-package communications, although the latencies are not nearly the magnitude we see inter-package. I've not seen such communication distance artifacts on the T2+, where the cache banks are connected to the cores via a high-speed crossbar instead of a ring -- communication latencies seem more regular.

  Read the article

• When is a Seek not a Seek?

  - by Paul White

  The following script creates a single-column clustered table containing the integers from 1 to 1,000 inclusive. IF OBJECT_ID(N'tempdb..#Test', N'U') IS NOT NULL DROP TABLE #Test ; GO CREATE TABLE #Test ( id INTEGER PRIMARY KEY CLUSTERED ); ; INSERT #Test (id) SELECT V.number FROM master.dbo.spt_values AS V WHERE V.[type] = N'P' AND V.number BETWEEN 1 AND 1000 ; Let’s say we need to find the rows with values from 100 to 170, excluding any values that divide exactly by 10.  One way to write that query would be: SELECT T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; That query produces a pretty efficient-looking query plan: Knowing that the source column is defined as an INTEGER, we could also express the query this way: SELECT T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; We get a similar-looking plan: If you look closely, you might notice that the line connecting the two icons is a little thinner than before.  The first query is estimated to produce 61.9167 rows – very close to the 63 rows we know the query will return.  The second query presents a tougher challenge for SQL Server because it doesn’t know how to predict the selectivity of the modulo expression (T.id % 10 > 0).  Without that last line, the second query is estimated to produce 68.1667 rows – a slight overestimate.  Adding the opaque modulo expression results in SQL Server guessing at the selectivity.  As you may know, the selectivity guess for a greater-than operation is 30%, so the final estimate is 30% of 68.1667, which comes to 20.45 rows. The second difference is that the Clustered Index Seek is costed at 99% of the estimated total for the statement.  For some reason, the final SELECT operator is assigned a small cost of 0.0000484 units; I have absolutely no idea why this is so, or what it models.  Nevertheless, we can compare the total cost for both queries: the first one comes in at 0.0033501 units, and the second at 0.0034054.  The important point is that the second query is costed very slightly higher than the first, even though it is expected to produce many fewer rows (20.45 versus 61.9167). If you run the two queries, they produce exactly the same results, and both complete so quickly that it is impossible to measure CPU usage for a single execution.  We can, however, compare the I/O statistics for a single run by running the queries with STATISTICS IO ON: Table '#Test'. Scan count 63, logical reads 126, physical reads 0. Table '#Test'. Scan count 01, logical reads 002, physical reads 0. The query with the IN list uses 126 logical reads (and has a ‘scan count’ of 63), while the second query form completes with just 2 logical reads (and a ‘scan count’ of 1).  It is no coincidence that 126 = 63 * 2, by the way.  It is almost as if the first query is doing 63 seeks, compared to one for the second query. In fact, that is exactly what it is doing.  There is no indication of this in the graphical plan, or the tool-tip that appears when you hover your mouse over the Clustered Index Seek icon.  To see the 63 seek operations, you have click on the Seek icon and look in the Properties window (press F4, or right-click and choose from the menu): The Seek Predicates list shows a total of 63 seek operations – one for each of the values from the IN list contained in the first query.  I have expanded the first seek node to show the details; it is seeking down the clustered index to find the entry with the value 101.  Each of the other 62 nodes expands similarly, and the same information is contained (even more verbosely) in the XML form of the plan. Each of the 63 seek operations starts at the root of the clustered index B-tree and navigates down to the leaf page that contains the sought key value.  Our table is just large enough to need a separate root page, so each seek incurs 2 logical reads (one for the root, and one for the leaf).  We can see the index depth using the INDEXPROPERTY function, or by using the a DMV: SELECT S.index_type_desc, S.index_depth FROM sys.dm_db_index_physical_stats ( DB_ID(N'tempdb'), OBJECT_ID(N'tempdb..#Test', N'U'), 1, 1, DEFAULT ) AS S ; Let’s look now at the Properties window when the Clustered Index Seek from the second query is selected: There is just one seek operation, which starts at the root of the index and navigates the B-tree looking for the first key that matches the Start range condition (id >= 101).  It then continues to read records at the leaf level of the index (following links between leaf-level pages if necessary) until it finds a row that does not meet the End range condition (id <= 169).  Every row that meets the seek range condition is also tested against the Residual Predicate highlighted above (id % 10 > 0), and is only returned if it matches that as well. You will not be surprised that the single seek (with a range scan and residual predicate) is much more efficient than 63 singleton seeks.  It is not 63 times more efficient (as the logical reads comparison would suggest), but it is around three times faster.  Let’s run both query forms 10,000 times and measure the elapsed time: DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON; SET STATISTICS XML OFF; ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; GO DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; On my laptop, running SQL Server 2008 build 4272 (SP2 CU2), the IN form of the query takes around 830ms and the range query about 300ms.  The main point of this post is not performance, however – it is meant as an introduction to the next few parts in this mini-series that will continue to explore scans and seeks in detail. When is a seek not a seek?  When it is 63 seeks © Paul White 2011 email: [email protected] twitter: @SQL_kiwi

  Read the article

• BizTalk: Internals: the Partner Direct Ports and the Orchestration Chains

  - by Leonid Ganeline

  Partner Direct Port is one of the BizTalk hidden gems. It opens simple ways to the several messaging patterns. This article based on the Kevin Lam’s blog article. The article is pretty detailed but it still leaves several unclear pieces. So I have created a sample and will show how it works from different perspectives. Requirements We should create an orchestration chain where the messages should be routed from the first stage to the second stage. The messages should not be modified. All messages has the same message type. Common artifacts Source code can be downloaded here. It is interesting but all orchestrations use only one port type. It is possible because all ports are one-way ports and use only one operation. I have added a B orchestration. It helps to test the sample, showing all test messages in channel. The Receive shape Filter is empty. A Receive Port (R_Shema1Direct) is a plain Direct Port. As you can see, a subscription expression of this direct port has only one part, the MessageType for our test schema: A Filer is empty but, as you know, a link from the Receive shape to the Port creates this MessageType expression. I use only one Physical Receive File port to send a message to all processes. Each orchestration outputs a Trace.WriteLine(“<Orchestration Name>”). Forward Binding This sample has three orchestrations: A_1, A_21 and A_22. A_1 is a sender, A_21 and A_22 are receivers. Here is a subscription of the A_1 orchestration: It has two parts A MessageType. The same was for the B orchestration. A ReceivePortID. There was no such parameter for the B orchestration. It was created because I have bound the orchestration port with Physical Receive File port. This binding means the PortID parameter is added to the subscription. How to set up the ports? All ports involved in the message exchange should be the same port type. It forces us to use the same operation and the same message type for the bound ports. This step as absolutely contra-intuitive. We have to choose a Partner Orchestration parameter for the sending orchestration, A_1. The first strange thing is it is not a partner orchestration we have to choose but an orchestration port. But the most strange thing is we have to choose exactly this orchestration and exactly this port.It is not a port from the partner, receive orchestrations, A_21 or A_22, but it is A_1 orchestration and S_SentFromA_1 port. Now we have to choose a Partner Orchestration parameter for the received orchestrations, A_21 and A_22. Nothing strange is here except a parameter name. We choose the port of the sender, A_1 orchestration and S_SentFromA_1 port. As you can see the Partner Orchestration parameter for the sender and receiver orchestrations is the same. Testing I dropped a test file in a file folder. There we go: A dropped file was received by B and by A_1 A_1 sent a message forward. A message was received by B, A_21, A_22 Let’s look at a context of a message sent by A_1 on the second step: A MessageType part. It is quite expected. A PartnerService, a ParnerPort, an Operation. All those parameters were set up in the Partner Orchestration parameter on both bound ports.     Now let’s see a subscription of the A_21 and A_22 orchestrations. Now it makes sense. That’s why we have chosen such a strange value for the Partner Orchestration parameter of the sending orchestration. Inverse Binding This sample has three orchestrations: A_11, A_12 and A_2. A_11 and A_12 are senders, A_2 is receiver. How to set up the ports? All ports involved in the message exchange should be the same port type. It forces us to use the same operation and the same message type for the bound ports. This step as absolutely contra-intuitive. We have to choose a Partner Orchestration parameter for a receiving orchestration, A_2. The first strange thing is it is not a partner orchestration we have to choose but an orchestration port. But the most strange thing is we have to choose exactly this orchestration and exactly this port.It is not a port from the partner, sent orchestrations, A_11 or A_12, but it is A_2 orchestration and R_SentToA_2 port. Now we have to choose a Partner Orchestration parameter for the sending orchestrations, A_11 and A_12. Nothing strange is here except a parameter name. We choose the port of the sender, A_2 orchestration and R_SentToA_2 port. Testing I dropped a test file in a file folder. There we go: A dropped file was received by B, A_11 and by A_12 A_11 and A_12 sent two messages forward. The messages were received by B, A_2 Let’s see what was a context of a message sent by A_1 on the second step: A MessageType part. It is quite expected. A PartnerService, a ParnerPort, an Operation. All those parameters were set up in the Partner Orchestration parameter on both bound ports. Here is a subscription of the A_2 orchestration. Models I had a hard time trying to explain the Partner Direct Ports in simple terms. I have finished with this model: Forward Binding Receivers know a Sender. Sender doesn’t know Receivers. Publishers know a Subscriber. Subscriber doesn’t know Publishers. 1 –> 1 1 –> M Inverse Binding Senders know a Receiver. Receiver doesn’t know Senders. Subscribers know a Publisher. Publisher doesn’t know Subscribers. 1 –> 1 M –> 1 Notes   Orchestration chain It’s worth to note, the Partner Direct Port Binding creates a chain opened from one side and closed from another. The Forward Binding: A new Receiver can be added at run-time. The Sender can not be changed without design-time changes in Receivers. The Inverse Binding: A new Sender can be added at run-time. The Receiver can not be changed without design-time changes in Senders.

  Read the article

• Specs, Form and Function – What am I Missing?

  - by Barry Shulam

  0 0 1 628 3586 08041 29 8 4206 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Friday October 26th the Microsoft Surface RT arrived at the office.  I was summoned to my boss’s office for the grand unpacking.  If I had planned ahead I could have used my iPhone 4 to film the event and post it on YouTube however the desire to hold the device and turn it ON was more inviting than becoming a proxy reviewer for Engadget’s website.  1980 was the first time we had a personal computer in our house.  It was a  Kaypro computer. It weighed 29 pounds more than any persons lap could hold.  Then the term “portable computer” meant you could remove it from the building and take it else where.  Today I am typing on this entry on a Macbook Air which weighs 2.38 pounds. This morning Amazons front page main title is: “Much More for Much Less” I was born at the right time to start with the CPM operating system on the Kaypro thru the DOS, Windows, Linux, Mac OSX and mobile phone operating systems and languages.  If you are not aware Technology is moving at a rapid pace.  The New iPad (those who are keeping score – iPad4) is replacing a 7 month old machine the New iPad (iPad 3) I have used and owned many technology devices in my life.  The main point that most of the reader who are in the USA overlook is the fact that we are in the USA.  The devices we purchase have a great digital garden to support them.  The Kaypro computer had a 7-inch screen.  It was a TV tube with two colors – Black and Green.  You could see the 80-column screen flicker with characters – have you every played Pac-Man emulated on the screen with the ABC characters. Traveling across the world you will find that not all apps on your device will function as they did back home because they are not offered outside of your country of origin. I think the main question a buyer of technology should be asking is Function.  The greatest Specs with out function limit you.  The most beautiful form with out function is the same as a crystal vase on your shelf – not a good cereal bowl in the morning. Microsoft Surface RT, Amazon Kindle Fire and Apple iPad all great devices in their respective customers hands. My advice for those looking to purchase on this year:  If the device is your only technology device you buy what you WANT and LIKE. Consider this parallel universe if its not your only device?  Ever go shopping for clothing, shoes, and accessories with your wife, girlfriend, sister or mother?  If you listen carefully you will hear the little voices coming out of there heads saying:  “This goes well with that and I can use it also with that outfit” ”Do you think this clashes with that?”  “Ohh I love how that combination looks on you”.  Portable devices such as tablets and computers can offer a whole lot more when they are combined with the digital echo system you have at home and the manufacturer offers online. Pros of each Device: Microsoft Surface RT: There is a new functionality named SmartGlass which will let you share the content off your tablet to your XBOX 360.  Microsoft office is loaded on the tablet.  You can have more than one user profile on the tablet if you share it with others.   Amazon Kindle or Kindle HD: If you are an Amazon consumer with an annual Amazon Prime service you can consume videos and read books off the Amazon site.  Its the cheapest device.  Its a step up from the kindle reader in many ways.   Apple Ipad or Ipad mini: Over 270 Thousand applications.  Airplay permits you the ability to share to your TV screen. If you are a cord cutter (a person who gets their entertainment content over the web or air vs Cable Providers) the Airplay or Smart glass are a huge bonus.  iPad mini or not: The mini will fit in a purse where the larger one will not.  Its lighter which makes it nice to hold for prolonged periods.  It has an option for LTE wireless which non of the other sub 9 inch tables offer.  The screen is non retina which means the applications are smaller.  Speaking with individuals who are above 50 in age that wear glasses they retina does not make a difference for them however they prefer the larger iPad over the new mini.   Happy Shopping this Channuka Season.   The Kosher Coder.   Follow me on twitter @KosherCoder

  Read the article

• Oracle Certification and virtualization Solutions.

  - by scoter

  As stated in official MOS ( My Oracle Support ) document 249212.1 support for Oracle products on non-Oracle VM platforms follow exactly the same stance as support for VMware and, so, the only x86 virtualization software solution certified for any Oracle product is "Oracle VM". Based on the fact that: Oracle VM is totally free ( you have the option to buy Oracle-Support ) Certified is pretty different from supported ( OracleVM is certified, others could be supported ) With Oracle VM you may not require to reproduce your issue(s) on physical server Oracle VM is the only x86 software solution that allows hard-partitioning *** *** see details to these Oracle public links: http://www.oracle.com/technetwork/server-storage/vm/ovm-hardpart-168217.pdf http://www.oracle.com/us/corporate/pricing/partitioning-070609.pdf people started asking to migrate from third party virtualization software (ex. RH KVM, VMWare) to Oracle VM. Migrating RH KVM guest to Oracle VM. OracleVM has a built-in P2V utility ( Official Documentation ) but in some cases we can't use it, due to : network inaccessibility between hypervisors ( KVM and OVM ) network slowness between hypervisors (KVM and OVM) size of the guest virtual-disks Here you'll find a step-by-step guide to "manually" migrate a guest machine from KVM to OVM. 1. Verify source guest characteristics. Using KVM web console you can verify characteristics of the guest you need to migrate, such as: CPU Cores details Defined Memory ( RAM ) Name of your guest Guest operating system Disks details ( number and size ) Network details ( number of NICs and network configuration ) 2. Export your guest in OVF / OVA format.  The export from Redhat KVM ( kernel virtual machine ) will create a structured export of your guest: [root@ovmserver1 mnt]# lltotal 12drwxrwx--- 5 36 36 4096 Oct 19 2012 b8296fca-13c4-4841-a50f-773b5139fcee b8296fca-13c4-4841-a50f-773b5139fcee is the ID of the guest exported from RH-KVM [root@ovmserver1 mnt]# cd b8296fca-13c4-4841-a50f-773b5139fcee/[root@ovmserver1 b8296fca-13c4-4841-a50f-773b5139fcee]# ls -ltrtotal 12drwxr-x--- 4 36 36 4096 Oct 19  2012 masterdrwxrwx--- 2 36 36 4096 Oct 29  2012 dom_mddrwxrwx--- 4 36 36 4096 Oct 31  2012 images images contains your virtual-disks exported [root@ovmserver1 b8296fca-13c4-4841-a50f-773b5139fcee]# cd images/[root@ovmserver1 images]# ls -ltratotal 16drwxrwx--- 5 36 36 4096 Oct 19  2012 ..drwxrwx--- 2 36 36 4096 Oct 31  2012 d4ef928d-6dc6-4743-b20d-568b424728a5drwxrwx--- 2 36 36 4096 Oct 31  2012 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1drwxrwx--- 4 36 36 4096 Oct 31  2012 .[root@ovmserver1 images]# cd d4ef928d-6dc6-4743-b20d-568b424728a5/[root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# ls -ltotal 5169092-rwxr----- 1 36 36 187904819200 Oct 31  2012 4c03b1cf-67cc-4af0-ad1e-529fd665dac1-rw-rw---- 1 36 36          341 Oct 31  2012 4c03b1cf-67cc-4af0-ad1e-529fd665dac1.meta[root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# file 4c03b1cf-67cc-4af0-ad1e-529fd665dac14c03b1cf-67cc-4af0-ad1e-529fd665dac1: LVM2 (Linux Logical Volume Manager) , UUID: sZL1Ttpy0vNqykaPahEo3hK3lGhwspv 4c03b1cf-67cc-4af0-ad1e-529fd665dac1 is the first exported disk ( physical volume ) [root@ovmserver1 d4ef928d-6dc6-4743-b20d-568b424728a5]# cd ../4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/[root@ovmserver1 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1]# ls -ltotal 5568076-rwxr----- 1 36 36 107374182400 Oct 31  2012 9020f2e1-7b8a-4641-8f80-749768cc237a-rw-rw---- 1 36 36          341 Oct 31  2012 9020f2e1-7b8a-4641-8f80-749768cc237a.meta[root@ovmserver1 4b241ea0-43aa-4f3b-ab7d-2fc633b491a1]# file 9020f2e1-7b8a-4641-8f80-749768cc237a9020f2e1-7b8a-4641-8f80-749768cc237a: x86 boot sector; partition 1: ID=0x83, active, starthead 1, startsector 63, 401562 sectors; partition 2: ID=0x82, starthead 0, startsector 401625, 65529135 sectors; startsector 63, 401562 sectors; partition 2: ID=0x82, starthead 0, startsector 401625, 65529135 sectors; partition 3: ID=0x83, starthead 254, startsector 65930760, 8385930 sectors; partition 4: ID=0x5, starthead 254, startsector 74316690, 135395820 sectors, code offset 0x48 9020f2e1-7b8a-4641-8f80-749768cc237a is the second exported disk, with partition 1 bootable 3. Prepare the new guest on Oracle VM. By Ovm-Manager we can prepare the guest where we will move the exported virtual-disks; under the Tab "Servers and VMs": click on  and create your guest with parameters collected before (point 1): - add NICs on different networks: - add virtual-disks; in this case we add two disks of 1.0 GB each one; we will extend the virtual disk copying the source KVM virtual-disk ( see next steps ) - verify virtual-disks created ( under Repositories tab ) 4. Verify OVM virtual-disks names. [root@ovmserver1 VirtualMachines]# grep -r hyptest_rdbms * 0004fb0000060000a906b423f44da98e/vm.cfg:OVM_simple_name = 'hyptest_rdbms' [root@ovmserver1 VirtualMachines]# cd 0004fb0000060000a906b423f44da98e [root@ovmserver1 0004fb0000060000a906b423f44da98e]# more vm.cfgvif = ['mac=00:21:f6:0f:3f:85,bridge=0004fb001089128', 'mac=00:21:f6:0f:3f:8e,bridge=0004fb00101971d'] OVM_simple_name = 'hyptest_rdbms' vnclisten = '127.0.0.1' disk = ['file:/OVS/Repositories/0004fb00000300004f17b7368139eb41/ VirtualDisks/0004fb000012000097c1bfea9834b17d.img,xvda,w', 'file:/OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img,xvdb,w'] vncunused = '1' uuid = '0004fb00-0006-0000-a906-b423f44da98e' on_reboot = 'restart' cpu_weight = 27500 memory = 32768 cpu_cap = 0 maxvcpus = 8 OVM_high_availability = True maxmem = 32768 vnc = '1' OVM_description = '' on_poweroff = 'destroy' on_crash = 'restart' name = '0004fb0000060000a906b423f44da98e' guest_os_type = 'linux' builder = 'hvm' vcpus = 8 keymap = 'en-us' OVM_os_type = 'Oracle Linux 5' OVM_cpu_compat_group = '' OVM_domain_type = 'xen_hvm' disk2 ovm ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img disk1 ovm ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb000012000097c1bfea9834b17d.img Summarizing disk1 --source ==> /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/9020f2e1-7b8a-4641-8f80-749768cc237a disk1 --dest ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb000012000097c1bfea9834b17d.img disk2 --source ==> /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/d4ef928d-6dc6-4743-b20d-568b424728a5/4c03b1cf-67cc-4af0-ad1e-529fd665dac1 disk2 --dest ==> /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/ 0004fb0000120000cde6a11c3cb1d0be.img 5. Copy KVM exported virtual-disks to OVM virtual-disks. Keeping your Oracle VM guest stopped you can copy KVM exported virtual-disks to OVM virtual-disks; what I did is only to locally mount the filesystem containing the exported virtual-disk ( by an usb device ) on my OVS; the copy automatically resize OVM virtual-disks ( previously created with a size of 1GB ) . nohup cp /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/4b241ea0-43aa-4f3b-ab7d-2fc633b491a1/9020f2e1-7b8a-4641-8f80-749768cc237a /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/0004fb000012000097c1bfea9834b17d.img & nohup cp /mnt/b8296fca-13c4-4841-a50f-773b5139fcee/images/d4ef928d-6dc6-4743-b20d-568b424728a5/4c03b1cf-67cc-4af0-ad1e-529fd665dac1 /OVS/Repositories/0004fb00000300004f17b7368139eb41/VirtualDisks/0004fb0000120000cde6a11c3cb1d0be.img & 7. When copy completed refresh repository to aknowledge the new-disks size. 7. After "refresh repository" is completed, start guest machine by Oracle VM manager. After the first start of your guest: - verify that you can see all disks and partitions - verify that your guest is network reachable ( MAC Address of your NICs changed ) Eventually you can also evaluate to convert your guest to PVM ( Paravirtualized virtual Machine ) following official Oracle documentation. Ciao Simon COTER ps: next-time I'd like to post an article reporting how to manually migrate Virtual-Iron guests to OracleVM.  Comments and corrections are welcome. 

  Read the article

• Different Not Automatically Implies Better

  - by Alois Kraus

  Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/11/05/154556.aspxRecently I was digging deeper why some WCF hosted workflow application did consume quite a lot of memory although it did basically only load a xaml workflow. The first tool of choice is Process Explorer or even better Process Hacker (has more options and the best feature copy&paste does work). The three most important numbers of a process with regards to memory are Working Set, Private Working Set and Private Bytes. Working set is the currently consumed physical memory (parts can be shared between processes e.g. loaded dlls which are read only) Private Working Set is the physical memory needed by this process which is not shareable Private Bytes is the number of non shareable which is only visible in the current process (e.g. all new, malloc, VirtualAlloc calls do create private bytes) When you have a bigger workflow it can consume under 64 bit easily 500MB for a 1-2 MB xaml file. This does not look very scalable. Under 64 bit the issue is excessive private bytes consumption and not the managed heap. The picture is quite different for 32 bit which looks a bit strange but it seems that the hosted VB compiler is a lot less memory hungry under 32 bit. I did try to repro the issue with a medium sized xaml file (400KB) which does contain 1000 variables and 1000 if which can be represented by C# code like this: string Var1; string Var2; ... string Var1000; if (!String.IsNullOrEmpty(Var1) ) { Console.WriteLine(“Var1”); } if (!String.IsNullOrEmpty(Var2) ) { Console.WriteLine(“Var2”); } ....   Since WF is based on VB.NET expressions you are bound to the hosted VB.NET compiler which does result in (x64) 140 MB of private bytes which is ca. 140 KB for each if clause which is quite a lot if you think about the actually present functionality. But there is hope. .NET 4.5 does allow now C# expressions for WF which is a major step forward for all C# lovers. I did create some simple patcher to “cross compile” my xaml to C# expressions. Lets look at the result: C# Expressions VB Expressions x86 x86 On my home machine I have only 32 bit which gives you quite exactly half of the memory consumption under 64 bit. C# expressions are 10 times more memory hungry than VB.NET expressions! I wanted to do more with less memory but instead it did consume a magnitude more memory. That is surprising to say the least. The workflow does initialize in about the same time under x64 and x86 where the VB code does it in 2s whereas the C# version needs 18s. Also nearly ten times slower. That is a too high price to pay for any bigger sized xaml workflow to convert from VB.NET to C# expressions. If I do reduce the number of expressions to 500 then it does need 400MB which is about half of the memory. It seems that the cost per if does rise linear with the number of total expressions in a xaml workflow.  Expression Language Cost per IF Startup Time C# 1000 Ifs x64 1,5 MB 18s C# 500 Ifs x64 750 KB 9s VB 1000 Ifs x64 140 KB 2s VB 500 Ifs x64 70 KB 1s Now we can directly compare two MS implementations. It is clear that the VB.NET compiler uses the same underlying structure but it has much higher offset compared to the highly inefficient C# expression compiler. I have filed a connect bug here with a harsher wording about recent advances in memory consumption. The funniest thing is that one MS employee did give an Azure AppFabric demo around early 2011 which was so slow that he needed to investigate with xperf. He was after startup time and the call stacks with regards to VB.NET expression compilation were remarkably similar. In fact I only found this post by googling for parts of my call stacks. … “C# expressions will be coming soon to WF, and that will have different performance characteristics than VB” … What did he know Jan 2011 what I did no know until today? ;-). He knew that C# expression will come but that they will not be automatically have better footprint. It is about time to fix that. In its current state C# expressions are not usable for bigger workflows. That also explains the headline for today. You can cheat startup time by prestarting workflows so that the demo looks nice and snappy but it does hurt scalability a lot since you do need much more memory than necessary. I did find the stacks by enabling virtual allocation tracking within XPerf which is still the best tool out there. But first you need to look at your process to check where the memory is hiding: For the C# Expression compiler you do not need xperf. You can directly dump the managed heap and check with a profiler of your choice. But if the allocations are happening on the Private Data ( VirtualAlloc ) you can find it with xperf. There is a nice video on channel 9 explaining VirtualAlloc tracking it in greater detail. If your data allocations are on the Heap it does mean that the C/C++ runtime did create a heap for you where all malloc, new calls do allocate from it. You can enable heap tracing with xperf and full call stack support as well which is doable via xperf like it is shown also on channel 9. Or you can use WPRUI directly: To make “Heap Usage” it work you need to set for your executable the tracing flags (before you start it). For example devenv.exe HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\devenv.exe DWORD TracingFlags 1 Do not forget to disable it after you did complete profiling the process or it will impact the startup time quite a lot. You can with xperf attach directly to a running process and collect heap allocation information from a gone wild process. Very handy if you need to find out what a process was doing which has arrived in a funny state. “VirtualAlloc usage” does work without explicitly enabling stuff for a specific process and is always on machine wide. I had issues on my Windows 7 machines with the call stack collection and the latest Windows 8.1 Performance Toolkit. I was told that WPA from Windows 8.0 should work fine but I do not want to downgrade.

  Read the article

• Wired connection periodically disconnects requires ipconfig /release and /renew to reconnect

  - by Sesame

  I just got back into University and after a day of using the internet I suddenly was unable to visit other webpages even though I was still able to chat. I restarted the computer and the internet could no longer visit webpages at all. I got a DNS error from the browser (chrome) and the troubleshooter. The connection comes up as "Network 3" even though It was "Network 2" when it worked. I compared ipconfig /all logs and they seemed identical when it was and was not working. I've found two ways to get internet connection (they no longer work): run ipconfig /release and ipconfig /renew several times set a random address and have the troubleshooter fix the new found dhcp problem (before it says dns cannot fix). I checked and it said DHCP was enabled. But either step one or two usually needs to be repeated several times before the network will change back to "network 2" from the defunct "network 3" and after an hour or so I have problems again. I've tried: Uninstalling windows defender and turning off firewall (windows firewall). Updating Qualcomm Ethernet driver - it is up to date. System Restore (problem resurfaces quickly...it's possible this has something to do with windows update?) Flushing dns and setting dns myself (google one and others). Booting in safe mode with networking...didn't fix anything Reinstalling Ethernet Driver Using other ethernet cable, other wall port. I'm out of ideas. Ipconfig /all: Windows IP Configuration Host Name . . . . . . . . . . . . : NGoller Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : Home Ethernet adapter UConnect: Connection-specific DNS Suffix . : Home Description . . . . . . . . . . . : Qualcomm Atheros AR8151 PCI-E Gigabit Ethernet Controller Physical Address. . . . . . . . . : 90-2B-34-50-33-F4 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : fd00::2086:628:f0a1:73c3(Preferred) Temporary IPv6 Address. . . . . . : fd00::c86b:370:b1d9:bd73(Preferred) Link-local IPv6 Address . . . . . : fe80::2086:628:f0a1:73c3%11(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.0.33(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Wednesday, August 28, 2013 11:58:37 PM Lease Expires . . . . . . . . . . : Thursday, August 29, 2013 11:58:37 PM Default Gateway . . . . . . . . . : 192.168.0.1 DHCP Server . . . . . . . . . . . : 192.168.0.1 DNS Servers . . . . . . . . . . . : 192.168.0.1 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.Home: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Home Description . . . . . . . . . . . : Microsoft ISATAP Adapter Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter Teredo Tunneling Pseudo-Interface: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes I'm getting these errors commonly: The IP address lease 155.97.227.199 for the Network Card with network address 0x902B345033F4 has been denied by the DHCP server 10.0.1.1 (The DHCP Server sent a DHCPNACK message). Event filter with query "SELECT * FROM __InstanceModificationEvent WITHIN 60 WHERE TargetInstance ISA "Win32_Processor" AND TargetInstance.LoadPercentage > 99" could not be reactivated in namespace "//./root/CIMV2" because of error 0x80041003. Events cannot be delivered through this filter until the problem is corrected. By the way, Operating System: Windows 7 - 64 Bit. Have downloaded latest windows updates. Update: And my two fixes don't work any more :( . This is now what happens when I try to Ipconfig /renew: C:\Users\Nikko\Desktop>ipconfig /renew Windows IP Configuration An error occurred while renewing interface Local Area Connection : The name spec ified in the network control block (NCB) is in use on a remote adapter. The NCB is the data. An error occurred while releasing interface Loopback Pseudo-Interface 1 : The sy stem cannot find the file specified. Update 2: So my internet is randomly working again today. The IP address I had before was a local one while the university address should start with 155... I didn't do anything to the settings...it's bizarre that it all of a sudden works. Thanks!

  Read the article

• From the Classroom to the Boardroom

  - by Maria Sandu

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Pens and Paper...these are the only things being a student and being a graduate / professional have in common. Walking in to the offices of Oracle South Africa as a graduate the first thing you notice is how polished and sleek all the people who work here look. 80% of the ladies wear sky-scraper heels and walk with the greatest grace. This was the first of many rude awakenings to remind me that I am no longer a student but a graduate. My first struggle was having to wake up at wee hours of the morning to prepare for work. As a student going to class was almost an optional thing, if you missed a morning class you could always attend an evening class to make up for it or simply attend with another group. But in the workplace, you HAVE to show up every single morning at the same time, with no option of coming in when it suits you and there is definitely no coming in with the evening class/shift. As a student, the earliest hour I ever woke up was 7:00am, anything earlier than that was considered inhumane torture. My reason for waking up every morning as a student was “you have a degree to go get” but as a graduate having to go to work I have to say to myself “here’s to a new day of learning and growing”. My second struggle has come in having to change my beloved wardrobe. Everyone who knows me knows how passionate I am about fashion and shopping. For me Shopping is a BASIC HUMAN RIGHT, that should not be messed with. Therefore it was with great sadness that I swopped my rippled skinny jeans for pin-striped formal pants, my long chandelier earrings for simple studs, my flat shoes for heels, my sheer blouses for crisp white shirts, even my beloved wild hair had to make way for a simple ponytail. Our looks as ladies also came under great scrutiny, we had to acquaint ourselves with some serious grooming tools: the mascara, blush, lip-gloss, blush, a touch of lipstick and a manicure set. Language was a struggle of its own as well. Being a student you learn to relate to your peers in a informal way. In the workplace you have to address everyone with the same respect, including your peers. Words like “Hey buddy” had to make way for “good morning friend”. The month long winter school holiday was one of the things I looked forward to as a student. This was a time where we got to be at home and avoid the coldest month of the year, July. It was the most amazing thing ever, just sleeping and snuggling up to all sorts of warm things but sadly it is now a thing of the past. It is currently winter in South Africa and going to work has become the most unfashionable thing with all the jackets, boots, scarves and gloves. But summer is coming and I will miss those holidays too. As a student the school holidays were like a gift for us to catch a break and not think for a while which was why it was imaginable how someone would go on for the entire year without a break, with only the promise of a mere 21 days annual leave!! Right now I am sure we are all looking forward to taking that annual leave when the time is right. The worst rude awakening I must say, has to be presenting in front of clients and managers. As a student you have the same class mates for almost four years therefore presenting in front of them becomes the norm over the years and your lecturer will always go gently on you. What they don’t tell you at University is that in the real world, time is money and clients pay money to see you present therefore there is no room for error. Clients are not there to give you a score and boost your ego, they expect nothing less than 100% and they will let you know without a second thought. For a graduate this can feel like you are being fed to the sharks, you either get eaten or you swim for your life. At the end of the day, it is all an experience that is meant to groom us into better professional and make us a part of the Red Team. All the sacrifices are worth it and they lead us to being better and more polished professionals. So if you are interested in joining the ECEMEA Sales and Presales Internship Programme, please have a look at http://campus.oracle.com for more information and for our latest vacancies and internships. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  Read the article

• ndd on Solaris 10

  - by user12620111

  This is mostly a repost of LaoTsao's Weblog with some tweaks. Last time that I tried to cut & paste directly off of his page, some of the XML was messed up. I run this from my MacBook. It should also work from your windows laptop if you use cygwin. ================If not already present, create a ssh key on you laptop================ # ssh-keygen -t rsa ================ Enable passwordless ssh from my laptop. Need to type in the root password for the remote machines. Then, I no longer need to type in the password when I ssh or scp from my laptop to servers. ================ #!/usr/bin/env bash for server in `cat servers.txt` do   echo root@$server   cat ~/.ssh/id_rsa.pub | ssh root@$server "cat >> .ssh/authorized_keys" done ================ servers.txt ================ testhost1testhost2 ================ etc_system_addins ================ set rpcmod:clnt_max_conns=8 set zfs:zfs_arc_max=0x1000000000 set nfs:nfs3_bsize=131072 set nfs:nfs4_bsize=131072 ================ ndd-nettune.txt ================ #!/sbin/sh # # ident   "@(#)ndd-nettune.xml    1.0     01/08/06 SMI" . /lib/svc/share/smf_include.sh . /lib/svc/share/net_include.sh # Make sure that the libraries essential to this stage of booting  can be found. LD_LIBRARY_PATH=/lib; export LD_LIBRARY_PATH echo "Performing Directory Server Tuning..." >> /tmp/smf.out # # Standard SuperCluster Tunables # /usr/sbin/ndd -set /dev/tcp tcp_max_buf 2097152 /usr/sbin/ndd -set /dev/tcp tcp_xmit_hiwat 1048576 /usr/sbin/ndd -set /dev/tcp tcp_recv_hiwat 1048576 # Reset the library path now that we are past the critical stage unset LD_LIBRARY_PATH ================ ndd-nettune.xml ================ <?xml version="1.0"?> <!DOCTYPE service_bundle SYSTEM "/usr/share/lib/xml/dtd/service_bundle.dtd.1"> <!-- ident "@(#)ndd-nettune.xml 1.0 04/09/21 SMI" --> <service_bundle type='manifest' name='SUNWcsr:ndd'>   <service name='network/ndd-nettune' type='service' version='1'>     <create_default_instance enabled='true' />     <single_instance />     <dependency name='fs-minimal' type='service' grouping='require_all' restart_on='none'>       <service_fmri value='svc:/system/filesystem/minimal' />     </dependency>     <dependency name='loopback-network' grouping='require_any' restart_on='none' type='service'>       <service_fmri value='svc:/network/loopback' />     </dependency>     <dependency name='physical-network' grouping='optional_all' restart_on='none' type='service'>       <service_fmri value='svc:/network/physical' />     </dependency>     <exec_method type='method' name='start' exec='/lib/svc/method/ndd-nettune' timeout_seconds='3' > </exec_method>     <exec_method type='method' name='stop'  exec=':true'                       timeout_seconds='3' > </exec_method>     <property_group name='startd' type='framework'>       <propval name='duration' type='astring' value='transient' />     </property_group>     <stability value='Unstable' />     <template>       <common_name>     <loctext xml:lang='C'> ndd network tuning </loctext>       </common_name>       <documentation>     <manpage title='ndd' section='1M' manpath='/usr/share/man' />       </documentation>     </template>   </service> </service_bundle> ================ system_tuning.sh ================ #!/usr/bin/env bash for server in `cat servers.txt` do   cat etc_system_addins | ssh root@$server "cat >> /etc/system"   scp ndd-nettune.xml root@${server}:/var/svc/manifest/site/ndd-nettune.xml   scp ndd-nettune.txt root@${server}:/lib/svc/method/ndd-nettune   ssh root@$server chmod +x /lib/svc/method/ndd-nettune   ssh root@$server svccfg validate /var/svc/manifest/site/ndd-nettune.xml   ssh root@$server svccfg import /var/svc/manifest/site/ndd-nettune.xml done

  Read the article

• Controlling the Sizing of the af:messages Dialog

  - by Duncan Mills

  Over the last day or so a small change in behaviour between 11.1.2.n releases of ADF and earlier versions has come to my attention. This has concerned the default sizing of the dialog that the framework automatically generates to handle the display of JSF messages being handled by the <af:messages> component. Unlike a normal popup, you don't have a physical <af:dialog> or <af:window> to set the sizing on in your page definition, so you're at the mercy of what the framework provides. In this case the framework now defines a fixed 250x250 pixel content area dialog for these messages, which can look a bit weird if the message is either very short, or very long. Unfortunately this is not something that you can control through the skin, instead you have to be a little more creative. Here's the solution I've come up with.  Unfortunately, I've not found a supportable way to reset the dialog so as to say  just size yourself based on your contents, it is actually possible to do this by tweaking the correct DOM objects, but I wanted to start with a mostly supportable solution that only uses the best practice of working through the ADF client side APIs. The Technique The basic approach I've taken is really very simple.  The af:messages dialog is just a normal richDialog object, it just happens to be one that is pre-defined for you with a particular known name "msgDlg" (which hopefully won't change). Knowing this, you can call the accepted APIs to control the content width and height of that dialog, as our meerkat friends would say, "simples" 1 The JavaScript For this example I've defined three JavaScript functions.   The first does all the hard work and is designed to be called from server side Java or from a page load event to set the default. The second is a utility function used by the first to validate the values you're about to use for height and width. The final function is one that can be called from the page load event to set an initial default sizing if that's all you need to do. Function resizeDefaultMessageDialog() /**  * Function that actually resets the default message dialog sizing.  * Note that the width and height supplied define the content area  * So the actual physical dialog size will be larger to account for  * the chrome containing the header / footer etc.  * @param docId Faces component id of the document  * @param contentWidth - new content width you need  * @param contentHeight - new content height  */ function resizeDefaultMessageDialog(docId, contentWidth, contentHeight) {   // Warning this value may change from release to release   var defMDName = "::msgDlg";   //Find the default messages dialog   msgDialogComponent = AdfPage.PAGE.findComponentByAbsoluteId(docId + defMDName); // In your version add a check here to ensure we've found the right object!   // Check the new width is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentWidth)){       msgDialogComponent.setContentWidth(contentWidth);   }   // Check the new height is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentHeight)){       msgDialogComponent.setContentHeight(contentHeight);   } }  Function dimensionIsValid()  /**  * Simple function to check that sensible numeric values are   * being proposed for a dimension  * @param sampleDimension   * @return booolean  */ function dimensionIsValid(sampleDimension){     return (!isNaN(sampleDimension) && sampleDimension > 0); } Function  initializeDefaultMessageDialogSize() /**  * This function will re-define the default sizing applied by the framework   * in 11.1.2.n versions  * It is designed to be called with the document onLoad event  */ function initializeDefaultMessageDialogSize(loadEvent){   //get the configuration information   var documentId = loadEvent.getSource().getProperty('documentId');   var newWidth = loadEvent.getSource().getProperty('defaultMessageDialogContentWidth');   var newHeight = loadEvent.getSource().getProperty('defaultMessageDialogContentHeight');   resizeDefaultMessageDialog(documentId, newWidth, newHeight); } Wiring in the Functions As usual, the first thing we need to do when using JavaScript with ADF is to define an af:resource  in the document metaContainer facet <af:document>   ....     <f:facet name="metaContainer">     <af:resource type="javascript" source="/resources/js/hackMessagedDialog.js"/>    </f:facet> </af:document> This makes the script functions available to call.  Next if you want to use the option of defining an initial default size for the dialog you use a combination of <af:clientListener> and <af:clientAttribute> tags like this. <af:document title="MyApp" id="doc1">   <af:clientListener method="initializeDefaultMessageDialogSize" type="load"/>   <af:clientAttribute name="documentId" value="doc1"/>   <af:clientAttribute name="defaultMessageDialogContentWidth" value="400"/>   <af:clientAttribute name="defaultMessageDialogContentHeight" value="150"/>  ...   Just in Time Dialog Sizing  So  what happens if you have a variety of messages that you might add and in some cases you need a small dialog and an other cases a large one? Well in that case you can re-size these dialogs just before you submit the message. Here's some example Java code: FacesContext ctx = FacesContext.getCurrentInstance();          //reset the default dialog size for this message ExtendedRenderKitService service =              Service.getRenderKitService(ctx, ExtendedRenderKitService.class); service.addScript(ctx, "resizeDefaultMessageDialog('doc1',100,50);");          FacesMessage msg = new FacesMessage("Short message"); msg.setSeverity(FacesMessage.SEVERITY_ERROR); ctx.addMessage(null, msg);  So there you have it. This technique should, at least, allow you to control the dialog sizing just enough to stop really objectionable whitespace or scrollbars. 1 Don't worry if you don't get the reference, lest's just say my kids watch too many adverts.

  Read the article

• What Counts for A DBA: Observant

  - by drsql

  When walking up to the building where I work, I can see CCTV cameras placed here and there for monitoring access to the building. We are required to wear authorization badges which could be checked at any time. Do we have enemies?  Of course! No one is 100% safe; even if your life is a fairy tale, there is always a witch with an apple waiting to snack you into a thousand years of slumber (or at least so I recollect from elementary school.) Even Little Bo Peep had to keep a wary lookout.    We nerdy types (or maybe it was just me?) generally learned on the school playground to keep an eye open for unprovoked attack from simpler, but more muscular souls, and take steps to avoid messy confrontations well in advance. After we’d apprehensively negotiated adulthood with varying degrees of success, these skills of watching for danger, and avoiding it,  translated quite well to the technical careers so many of us were destined for. And nowhere else is this talent for watching out for irrational malevolence so appropriate as in a career as a production DBA.   It isn’t always active malevolence that the DBA needs to watch out for, but the even scarier quirks of common humanity.  A large number of the issues that occur in the enterprise happen just randomly or even just one time ever in a spurious manner, like in the case where a person decided to download the entire MSDN library of software, cross join every non-indexed billion row table together, and simultaneously stream the HD feed of 5 different sporting events, making the network access slow while the corporate online sales just started. The decent DBA team, like the going, gets tough under such circumstances. They spring into action, checking all of the sources of active information, observes the issue is no longer happening now, figures that either it wasn’t the database’s fault and that the reboot of the whatever device on the network fixed the problem.  This sort of reactive support is good, and will be the initial reaction of even excellent DBAs, but it is not the end of the story if you really want to know what happened and avoid getting called again when it isn’t even your fault.   When fires start raging within the corporate software forest, the DBA’s instinct is to actively find a way to douse the flames and get back to having no one in the company have any idea who they are.  Even better for them is to find a way of killing a potential problem while the fires are small, long before they can be classified as raging. The observant DBA will have already been monitoring the server environment for months in advance.  Most troubles, such as disk space and security intrusions, can be predicted and dealt with by alerting systems, whereas other trouble can come out of the blue and requires a skill of observing ongoing conditions and noticing inexplicable changes that could signal an emerging problem.  You can’t automate the DBA, because the bankable skill of a DBA is in detecting the early signs of unexpected problems, and working out how to deal with them before anyone else notices them.    To achieve this, the DBA will check the situation as it is currently happening,  and in many cases is likely to have been the person who submitted the problem to the level 1 support person in the first place, just to let the support team know of impending issues (always well received, I tell you what!). Database and host computer settings, configurations, and even critical data might be profiled and captured for later comparisons. He’ll use Monitoring tools, built-in, commercial (Not to be too crassly commercial or anything, but there is one such tool is SQL Monitor) and lots of homebrew monitoring tools to monitor for problems and changes in the server environment.   You will know that you have it right when a support call comes in and you can look at your monitoring tools and quickly respond that “response time is well within the normal range, the query that supports the failing interface works perfectly and has actually only been called 67% as often as normal, so I am more than willing to help diagnose the problem, but it isn’t the database server’s fault and is probably a client or networking slowdown causing the interface to be used less frequently than normal.” And that is the best thing for any DBA to observe…

  Read the article

• Data Modeling: Logical Modeling Exercise

  - by swisscheese

  In trying to learn the art of data storage I have been trying to take in as much solid information as possible. PerformanceDBA posted some really helpful tutorials/examples in the following posts among others: is my data normalized? and Relational table naming convention. I already asked a subset question of this model here. So to make sure I understood the concepts he presented and I have seen elsewhere I wanted to take things a step or two further and see if I am grasping the concepts. Hence the purpose of this post, which hopefully others can also learn from. Everything I present is conceptual to me and for learning rather than applying it in some production system. It would be cool to get some input from PerformanceDBA also since I used his models to get started, but I appreciate all input given from anyone. As I am new to databases and especially modeling I will be the first to admit that I may not always ask the right questions, explain my thoughts clearly, or use the right verbage due to lack of expertise on the subject. So please keep that in mind and feel free to steer me in the right direction if I head off track. If there is enough interest in this I would like to take this from the logical to physical phases to show the evolution of the process and share it here on Stack. I will keep this thread for the Logical Diagram though and start new one for the additional steps. For my understanding I will be building a MySQL DB in the end to run some tests and see if what I came up with actually works. Here is the list of things that I want to capture in this conceptual model. Edit for V1.2 The purpose of this is to list Bands, their members, and the Events that they will be appearing at, as well as offer music and other merchandise for sale Members will be able to match up with friends Members can write reviews on the Bands, their music, and their events. There can only be one review per member on a given item, although they can edit their reviews and history will be maintained. BandMembers will have the chance to write a single Comment on Reviews about the Band they are associated with. Collectively as a Band only one Comment is allowed per Review. Members can then rate all Reviews and Comments but only once per given instance Members can select their favorite Bands, music, Merchandise, and Events Bands, Songs, and Events will be categorized into the type of Genre that they are and then further subcategorized into a SubGenre if necessary. It is ok for a Band or Event to fall into more then one Genre/SubGenre combination. Event date, time, and location will be posted for a given band and members can show that they will be attending the Event. An Event can be comprised of more than one Band, and multiple Events can take place at a single location on the same day Every party will be tied to at least one address and address history shall be maintained. Each party could also be tied to more then one address at a time (i.e. billing, shipping, physical) There will be stored profiles for Bands, BandMembers, and general members. So there it is, maybe a bit involved but could be a great learning tool for many hopefully as the process evolves and input is given by the community. Any input? EDIT v1.1 In response to PerformanceDBA U.3) That means no merchandise other than Band merchandise in the database. Correct ? That was my original thought but you got me thinking. Maybe the site would want to sell its own merchandise or even other merchandise from the bands. Not sure a mod to make for that. Would it require an entire rework of the Catalog section or just the identifying relationship that exists with the Band? Attempted a mod to sell both complete albums or song. Either way they would both be in electronic format only available for download. That is why I listed an Album as being comprised of Songs rather then 2 separate entities. U.5) I understand what you bring up about the circular relation with Favorite. I would like to get to this “It is either one Entity with some form of differentiation (FavoriteType) which identifies its treatment” but how to is not clear to me. What am I missing here? u.6) “Business Rules This is probably the only area you are weak in.” Thanks for the honest response. I will readdress these but I hope to clear up some confusion in my head first with the responses I have posted back to you. Q.1) Yes I would like to have Accepted, Rejected, and Blocked. I am not sure what you are referring to as to how this would change the logical model? Q.2) A person does not have to be a User. They can exist only as a BandMember. Is that what you are asking? Minor Issue Zero, One, or More…Oops I admit I forgot to give this attention when building the model. I am submitting this version as is and will address in a future version. I need to read up more on Constraint Checking to make sure I am understanding things. M.4) Depends if you envision OrderPurchase in the future. Can you expand as to what you mean here? EDIT V1.2 In response to PerformanceDBA input... Lessons learned. I was mixing the concept of Identifying / Non-Identifying and Cardinality (i.e. Genre / SubGenre), and doing so inconsistently to make things worse. Associative Tables are not required in Logical Diagrams as their many-to-many relationships can be depicted and then expanded in the Physical Model. I was overlooking the Cardinality in a lot of the relationships The importance of reading through relationships using effective Verb Phrases to reassure I am modeling what I want to accomplish. U.2) In the concept of this model it is only required to track a Venue as a location for an Event. No further data needs to be collected. With that being said Events will take place on a given EventDate and will be hosted at a Venue. Venues will host multiple events and possibly multiple events on a given date. In my new model my thinking was that EventDate is already tied to Event . Therefore, Venue will not need a relationship with EventDate. The 5th and 6th bullets you have listed under U.2) leave me questioning my thinking though. Am I missing something here? U.3) Is it time to move the link between Item and Band up to Item and Party instead? With the current design I don't see a possibility to sell merchandise not tied to the band as you have brought up. U.5) I left as per your input rather than making it a discrete Supertype/Subtype Relationship as I don’t see a benefit of having that type of roll up. Additional Revisions AR.1) After going through the exercise for FavoriteItem, I feel that Item to Review requires a many-to-many relationship so that is indicated. Necessary? Ok here we go for v1.3 I took a few days on this version, going back and forth with my design. Once the logical process is complete, as I want to see if I am on the right track, I will go through in depth what I had learned and the troubles I faced as a beginner going through this process. The big point for this version was it took throwing in some Keys to help see what I was missing in the past. Going through the process of doing a matrix proved to be of great help also. Regardless of anything, if it wasn't for the input given by PerformanceDBA I would still be a lost soul wondering in the dark. Who knows my current design might reaffirm that I still am, but I have learned a lot so I am know I at least have a flashlight in my hand. At this point in time I admit that I am still confused about identifying and non-identifying relationships. In my model I had to use non-identifying relationships with non nulls just to join the relationships I wanted to model. In reading a lot on the subject there seems to be a lot of disagreement and indecisiveness on the subject so I did what I thought represented the right things in my model. When to force (identifying) and when to be free (non-identifying)? Anyone have inputs? EDIT V1.4 Ok took the V1.3 inputs and cleaned things up for this V1.4 Currently working on a V1.5 to include attributes.

  Read the article

• HTTP Error 403.18 - Forbidden - asp.net mvc web api

  - by CoffeeCode

  I have deployed the default asp.net mvc 4 web api project to my windows server 2008 RC and am experiensing some issues with calling the web api actions. I'm quite new in the server/iis configuration part. I can open the home page, but the API part doesnt work. I'm getting such an error: HTTP Error 403.18 - Forbidden The specified request cannot be processed in the application pool that is configured for this resource on the Web server Module IIS Web Core Notification BeginRequest Handler StaticFile Error Code 0x00000000 Requested URL http://server.com:80/index.php?p=MvcApplication2_deploy/api/values/ Physical Path C:\Inetpub\vhosts\server.com\Webservice\index.php Logon Method Not yet determined Logon User Not yet determined I have checked Url Rewrite it is empty, have disabled WebDAV and also checked the Handler Mappings every thing seems to be ok there. Could any one give me some hints what could be wrong? Thanks!!!

  Read the article

• Random Windows application crashes on Windows Server Hyper-V Core 2012

  - by Marlamin

  We're having some issues with our Hyper-V Core 2012 R2 installation on a HP DL360G8. We have an identical server with Hyper-V Core 2012 (not R2) that does not have these issues. When logging off from the physical server/via remote desktop, we sometimes get this error: Configure-SMRemoting.exe - Application Error : The application was unable to start correctly (0xc0000142). Click OK to close the application. We've also once or twice seen a "memory could not be read" error mentioning LoginUI.exe (another Windows app in System32) but have been unable to get an exact description. It's rather worrying to get such errors on a fresh install of Hyper-V 2012 R2. Is this even anything to worry about? Things we've done: Memtest86+, no memory errors Checksummed the file that is crashing with the one in the verified correct ISO, files match Server firmware upgrade to latest firmware of all present hardware, no visible changes Remade the RAID5 array , no change Reinstalled a few times, no change Reinstall without applying Windows updates after, no change

  Read the article

• Make vmware virtual machine from HDD with bad sectros

  - by mike1616

  I have a notebook with a bad HDD (it has bad sectors). I would like make a virtual disk with VMware workstation from this computer. I installed VMware Workstation & VMware vCenter Converter Standalone Client on this notebook, then I used virtualize a physical machine. It started procedure but at 38% I got this error: FAILED: An error occurred during the conversion: 'BlockLevelVolumeCloneMgr::CloneVolume: Detected a write error during the cloning of volume \WindowsBitmapDriverVolumeId=[39-06-3A-06-00-02-13-4C-1D-00-00-00]. Error: 209 (type: 1, code: 13)' I Googled it and I think it means that I have bad sectors on the HDD. How can I solve this problem and make a virtual machine from HDD with bad sectors?

  Read the article

• What does 'Highest active time' for disk activity in Windows resource monitor mean?

  - by Nick R

  I know what the disk io, disk queue length and other measures are, but what does 'Highest active time' mean? Is it the amount of time it is busy handling requests, or something else? When it is high, does it mean the CPU is busy doing some IO work, or is it just indicating that the disk is busy handling requests? I'm trying to work out if 50% active time means that 50% of the time the disk is either seeking, reading or writing, rather than the kernel is spending 50% of it's time servicing IO requests. Edit Another quick data point here. If you look at the difference between an SSD and a physical disk, the SSD has significantly less activity, so I guess this really means the amount of time the operating system is waiting for the disk to respond and returning data.

  Read the article

• RightFax 9.3 Available Disk Space?

  - by dkirk

  We are currently running RightFax 9.3 as our fax server. I was just in the RightFax Enterprise Fax Manager resolving another problem and noticed 2 little red exclamation marks in the lower left hand pane. I have one beside "Available disk space for fax images" and one beside "Available disk space for fax database". Both are labeled with 5%? What is this? How can this be resolved? I have plenty of physical storage left on the server drives so I am curious as to which space it is referring to??

  Read the article

• Powershell import-module webadministration

  - by David

  Every time I execute this command invoke-command -computername REMOTEPC -scriptblock { import-module WebAdministration; new-item "$env:systemdrive\inetpub\testsite" -type directory; New-WebSite -Name TestSite -Port 81 -PhysicalPath "$env:systemdrive\inetpub\testsite" } I get the following error Invalid class string (Exception from HRESULT: 0x800401F3 (CO_E_CLASSSTRING)) + CategoryInfo : NotSpecified: (:) [Get-ChildItem], COMException + FullyQualifiedErrorId : System.Runtime.InteropServices.COMException,Microsoft.PowerShell.Commands.GetChildItemCommand The website is created successfully as far as I can see. The following command gives the same error when enumerating the testsite Invoke-Command -computername REMOTEPC { import-module webadministration; dir -path IIS:\Sites\ } Name ID State Physical Path Bindings PSComputerName Default Web Site 1 Started http *:80: REMOTEPC Invalid class string (Exception from HRESULT: 0x800401F3 (CO_E_CLASSSTRING)) + CategoryInfo : NotSpecified: (:) [Get-ChildItem], COMException + FullyQualifiedErrorId : System.Runtime.InteropServices.COMException,Microsoft.PowerShell.Commands.GetChildItemCo mmand Any suggestions would be appreciated

  Read the article

• How to change RDS licensing mode from 'per user/device' to 'Remote control for administrators' on Wi

  - by Prashant Mandhare

  We have installed windows 2008 R2 enterprise on a Dell server. This server is placed remotely in data center and only administrator is going to access it for maintenance purpose. No multiple users or client remote access is needed Now during 'remote desktop services' role installation network admin accidentally selected 'per user/device' licensing mode. Because of which now 120 days free try period is ticking. Since only administrator is going to access this server remotely we need to have 'Remote control for administrators' licensing mode (like windows 2003) on it. How we can change licensing mode from 'per user/device' to 'Remote control for administrators' on 2008 server? Also will it be possible to do this change remotely using RDC session itself? or do i need to change it using physical console (if remote access is gonna be disabled during switch)?

  Read the article

• Set Firefox viewport size

  - by Frenk

  I thought this would be easy, but turns out it's not. I need to set the Firefox viewport size to a given value (larger than my screen resolution). What I want is not to enlarge the application window, but to enlarge the size available to the html content. The viewport won't be physically larger, but will "tell" the html that it is, so that webpages will take more space (obviously making scrollbars visible). For example, let's say my physical Firefox window is 800x600 px. I'd like to set "viewport size=2", then the available space for the html to render would be 1600x1200. Web Developer has a resize feature but it doesn't work when you set a size larger than your screen resolution (in Windows 7). Thanks in advance (I hope my explanation makes some sense).

  Read the article

• SQL Cluster on Hyper V Failover Cluster

  - by Chris W

  We have a VM running SQL Server on a 6 node cluster of blades. The VM's data files are stored a SAN attached using a direct iSCSI connection. As this SQL server will be running a number of important databases we're debating whether we should be clustering the SQL Server or will the fact that the VM is running in the cluster itself sufficient to give us high availability. I'm used to running SQL clusters when dealing with physical servers but I'm a bit sketchy on what is best practice when all the servers are just VMs sat on Hyper V. If a blade running the VM fails I presume the VM will be started up on another load. I'm guessing the only benefit that adding a SQL cluster to the setup will give us it that the recovery time after a failure will be a little quicker? Are there any other benefits?

  Read the article

• How HP D2700 disk enclosure is monitored for alarms via SNMP

  - by VSAC

  We have HP D2700 disk enclosure and we would like to monitor D2700 (connected to HP Proliant DL360G8) for alarms.I have following questions regarding this. What are the options available for reporting D2700 hardware alarms (disk failure, power failure) via SNMP? We understand the D2700 to have an Ethernet interface for controller A and B and alarms are available via SNMP via this interface. Can anyone provide the actual alarms via this interface? (MIB and alarm list) As we have a number of D2700’s and would like to minimize the number of physical connections to the switch and associated IP addresses; Is there a mechanism to monitor the D2700 from the SCSI connected HPDL360 and raise SNMP alarms from the DL360 for hardware failures on the D2700? If so can anyone provide details and the actual alarms and MIB via this mechanism? Thanks!

  Read the article

< Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >