Search Results

Search found 22756 results on 911 pages for 'power query'.

Page 140/911 | < Previous Page | 136 137 138 139 140 141 142 143 144 145 146 147  | Next Page >

  • Question about joins and table with Millions of rows

    - by xRobot
    I have to create 2 tables: Magazine ( 10 millions of rows with these columns: id, title, genres, printing, price ) Author ( 180 millions of rows with these columns: id, name, magazine_id ) . Every author can write on ONLY ONE magazine and every magazine has more authors. So if I want to know all authors of Motors Magazine, I have to use this query: SELECT * FROM Author, Magazine WHERE ( Author.id = Magazine.id ) AND ( genres = 'Motors' ) The same applies to Printing and Price column. To avoid these joins with tables of millions of rows, I thought to use this tables: Magazine ( 10 millions of rows with this column: id, title, genres, printing, price ) Author ( 180 millions of rows with this column: id, name, magazine_id, genres, printing, price ) . and this query: SELECT * FROM Author WHERE genres = 'Motors' Is it a good approach ? I can use Postgresql or Mysql.

    Read the article

  • Appengine (python) returns empty for valid queries

    - by Grant
    I've got an app with around half a million 'records', each of which only stores three fields. I'd like to look up records by a string field with a query, but I'm running into problems. If I visit the console page, manually view a record and save it (without making changes) it shows up in a query: SELECT * FROM wordEntry WHERE wordStr = 'SomeString' If I don't do this, I get 'no results'. Does appengine need time to update? If so, how much? (I was also having trouble batch deleting and modifying data, but I was able to break the problem up into smaller chunks.)

    Read the article

  • SQL to get friends AND friends of friends of a user

    - by Enrique
    My MySQL tables structure is like this. USER int id varchar username FRIEND_LIST int user_id int friend_id For each friend relationship I insert 2 records in FRIEND_LIST. If user 1 is friend of user 2 then the next rows are inserted into FRIEND_LIST 1,2 2,1 I want to get the friends and friends of friends of an specific user. The select should return columns a, b, c. a: user_id b: friend_id c: username (username of friend_id ) If 1 is friend of 2 and 3. 2 is friend of 3, 4 and 5 3 is friend of 5,6,7 Then the query to get 1's friends and friends of friends should return: 1 2 two 1 3 three 2 1 one 2 3 three 2 4 four 2 5 five 3 1 one 3 5 five 3 6 six 3 7 seven Can I get this rows with a single query?

    Read the article

  • PHP While Loops from Arrays

    - by Michael
    I have a table that contains members names and a field with multiple ID numbers. I want to create a query that returns results where any values in the ID fields overlap with any values in the array. For example: lastname: Smith firstname: John id: 101, 103 I have Array #1 with the values 101, 102, 103 I want the query to output all members who have the values 101 or 102 or 103 listed in their id field with multiple ids listed. Array ( [0] => 101 [1] => 102 [2] => 103 ) $sql="SELECT firstname, lastname, id FROM members WHERE id LIKE '%".$array_num_1."%'"; $result=mysql_query($sql); while ($rows=mysql_fetch_array($result)) { echo $rows['lastname'].', '.$rows['firstname'].'-'.$rows['id']; }

    Read the article

  • SQLite table creation date

    - by legr3c
    Is there a way to query the creation date of a table in SQLite? I am new to SQL, overall. I just found this http://stackoverflow.com/questions/1171019/sql-server-table-creation-date-query. I am assuming that sqlite_master is the equivalent to sys.tables in SQLite. Is that correct? But then my sqlite_master table only has the columns "type", "name", "tbl_name", "rootpage" and "sql". If this is not possible in SQLite, what would be the best way to implement this functionality by myself?

    Read the article

  • SqlServer2008 + expensive union all

    - by Tim Mahy
    Hi al, we have 5 tables over which we should query with user search input throughout a stored procedure. We do a union all of the similar data inside a view. Because of this the view can not be materialized. We are not able to change these 5 tables drastically (like creating a 6th table that contains the similar data of the 5 tables and reference that new one from the 5 tables). The query is rather expensive / slow what are our other options? It's allowed to think outside the box. Unfortunately I cannot give more information like the table/view/SP definition because of customer confidentiality... greetings, Tim

    Read the article

  • MYSQL and the LIMIT clause

    - by Lizard
    I was wondering if adding a LIMIT 1 to a query would speed up the processing? For example... I have a query that will most of the time return 1 result, but will occasionaly return 10's, 100's or even 1000's of records. But I will only ever want the first record. Would the limit 1 speed things up or make no difference? I know I could use GROUP BY to return 1 result but that would just add more computation. Any thoughts gladly accepted! Thanks

    Read the article

  • Should I use integer primary IDs?

    - by arthurprs
    For example, I always generate an auto-increment field for the users table, but I also specify a UNIQUE index on their usernames. There are situations that I first need to get the userId for a given username and then execute the desired query, or use a JOIN in the desired query. It's 2 trips to the database or a JOIN vs. a varchar index. Should I use integer primary IDs? Is there a real performance benefit on INT over small VARCHAR indexes?

    Read the article

  • How to dynamically modify NHibernate load queries at runtime? EventListeners? Interceptors?

    - by snicker
    I need to modify the query used to load many-to-one references in my model. Specifically, I need to be able to further filter this data. Unfortunately, NH will not allow me to filter many-to-one relationships using the built in filtering system (?). I could just be doing something incorrect. Is there a hook where I can manually and dynamically modify the query used to load the data? Or an alternative to filters that will allow me to specify parameters? Background: I am working with a database that is using a form of revision control, with each entity having a natural ID PK, an EntityId, a RevisionValidTo and RevisionValidFrom field. There may be many rows using the same EntityId, which is the reference for other tables to join on, but the Revision ranges are mutually exclusive. Thus, the relationship is only many-to-one IIF the filter is applied. However, NH offers no way to specify a filter on many-to-one references (they do for collections...)

    Read the article

  • How extension methods work in background ?

    - by Freshblood
    I am just cuirous about behind of extension method mechanism.Some questions and answer appear in my mind. MyClass.OrderBy(x=>x.a).OrderBy(x=>x.b); I was guessing that mechanism was first orderby method works and order them by a member then returns sorted items in IEnumarable interface then next Orderby method of IEnumarable Order them for b paramater.But i am wrong when i look at this linq query. MyClass.Orderby(x=>x.a).ThenOrderBy(x=>x.b); this is slightly different and tells me that i am wrong.Because this is not ordering by a then b and not possible to have such result if i was right.This get me confuse enough... Similiar structure is possible to write withot extension methods as first query but second is not possible.This prove i am wrong . Can u explain it ?

    Read the article

  • How to get count of another table in a left join

    - by Sinan
    I have multiple tables post id Name 1 post-name1 2 post-name2 user id username 1 user1 2 user2 post_user post_id user_id 1 1 2 1 post_comments post_id comment_id 1 1 1 2 1 3 I am using a query like this: SELECT post.id, post.title, user.id AS uid, username FROM `post` LEFT JOIN post_user ON post.id = post_user.post_id LEFT JOIN user ON user.id = post_user.user_id ORDER BY post_date DESC It works as intended. However I would like the get the number of comments for each post too. So how can i modify the this query so I can get the count of comments. Any ideas?

    Read the article

  • Speed up multiple JDBC SQL querys?

    - by paddydub
    I'm working on a shortest path a* algorithm in java with a mysql db. I'm executing the following SQL Query approx 300 times in the program to find route connections from a database of 10,000 bus connections. It takes approx 6-7 seconds to execute the query 300 times. Any suggestions on how I can speed this up or any ideas on a different method i can use ? Thanks ResultSet rs = stmt.executeQuery("select * from connections" + " where Connections.From_Station_stopID ="+StopID+";"); while (rs.next()) { int id = rs.getInt("To_Station_id"); String routeID = rs.getString("To_Station_routeID"); Double lat = rs.getDouble("To_Station_lat"); Double lng = rs.getDouble("To_Station_lng"); int time = rs.getInt("Time"); }

    Read the article

  • Using SQL to get the Last Reply on a Post

    - by Anraiki
    I am trying to replicate a forum function by getting the last reply of a post. For clarity, see PHPBB: there are four columns, and the last column is what I like to replicate. I have my tables created as such: discussion_id (primary key) user_id parent_id comment status pubdate I was thinking of creating a Link Table that would update for each time the post is replied to. The link table would be as follow: discussion_id (primary key) last_user_id last_user_update However, I am hoping that theres a advance query to achieve this method. That is, grabbing each Parent Discussion, and finding the last reply in each of those Parent Discussions. Am I right that there is such a query?

    Read the article

  • Which field is explain telling me to index?

    - by shady
    I don't understand what this explain statement is saying. Which field needs an index?. The first line to me is confusing because ref is null. Here's the query I'm using: SELECT pp.property_id AS 'good_prop_id', pr.site_number AS 'pr.site_number', CONCAT(pr.site_street_name, ' ', pr.site_street_type) AS 'pr.partial_addr', pr.county FROM realval_newdb.preforeclosures AS pr INNER JOIN realval_newdb.properties_preforeclosures AS pp USE INDEX (mee_id) ON (pr.mee_id = pp.mee_id) INNER JOIN listings_copy AS lc ON (pr.site_number = lc.site_number) AND (lc.site_street_name = CONCAT(pr.site_street_name, ' ', pr.site_street_type)) WHERE lc.site_county = pr.county LIMIT 1; Can anyone help me optimize this query?

    Read the article

  • User has many computers, computers have many attributes in different tables, best way to JOIN?

    - by krismeld
    I have a table for users: USERS: ID | NAME | ---------------- 1 | JOHN | 2 | STEVE | a table for computers: COMPUTERS: ID | USER_ID | ------------------ 13 | 1 | 14 | 1 | a table for processors: PROCESSORS: ID | NAME | --------------------------- 27 | PROCESSOR TYPE 1 | 28 | PROCESSOR TYPE 2 | and a table for harddrives: HARDDRIVES: ID | NAME | ---------------------------| 35 | HARDDRIVE TYPE 25 | 36 | HARDDRIVE TYPE 90 | Each computer can have many attributes from the different attributes tables (processors, harddrives etc), so I have intersection tables like this, to link the attributes to the computers: COMPUTER_PROCESSORS: C_ID | P_ID | --------------| 13 | 27 | 13 | 28 | 14 | 27 | COMPUTER_HARDDRIVES: C_ID | H_ID | --------------| 13 | 35 | So user JOHN, with id 1 owns computer 13 and 14. Computer 13 has processor 27 and 28, and computer 13 has harddrive 35. Computer 14 has processor 27 and no harddrive. Given a user's id, I would like to retrieve a list of that user's computers with each computers attributes. I have figured out a query that gives me a somewhat of a result: SELECT computers.id, processors.id AS p_id, processors.name AS p_name, harddrives.id AS h_id, harddrives.name AS h_name, FROM computers JOIN computer_processors ON (computer_processors.c_id = computers.id) JOIN processors ON (processors.id = computer_processors.p_id) JOIN computer_harddrives ON (computer_harddrives.c_id = computers.id) JOIN harddrives ON (harddrives.id = computer_harddrives.h_id) WHERE computers.user_id = 1 Result: ID | P_ID | P_NAME | H_ID | H_NAME | ----------------------------------------------------------- 13 | 27 | PROCESSOR TYPE 1 | 35 | HARDDRIVE TYPE 25 | 13 | 28 | PROCESSOR TYPE 2 | 35 | HARDDRIVE TYPE 25 | But this has several problems... Computer 14 doesnt show up, because it has no harddrive. Can I somehow make an OUTER JOIN to make sure that all computers show up, even if there a some attributes they don't have? Computer 13 shows up twice, with the same harddrive listet for both. When more attributes are added to a computer (like 3 blocks of ram), the number of rows returned for that computer gets pretty big, and it makes it had to sort the result out in application code. Can I somehow make a query, that groups the two returned rows together? Or a query that returns NULL in the h_name column in the second row, so that all values returned are unique? EDIT: What I would like to return is something like this: ID | P_ID | P_NAME | H_ID | H_NAME | ----------------------------------------------------------- 13 | 27 | PROCESSOR TYPE 1 | 35 | HARDDRIVE TYPE 25 | 13 | 28 | PROCESSOR TYPE 2 | 35 | NULL | 14 | 27 | PROCESSOR TYPE 1 | NULL | NULL | Or whatever result that make it easy to turn it into an array like this [13] => [P_NAME] => [0] => PROCESSOR TYPE 1 [1] => PROCESSOR TYPE 2 [H_NAME] => [0] => HARDDRIVE TYPE 25 [14] => [P_NAME] => [0] => PROCESSOR TYPE 1

    Read the article

  • How to join table to itself and select max values in SQL

    - by Jakub Konop
    I have a contracts table: contractId date price partId 1 20120121 10 1 2 20110130 9 1 3 20130101 15 2 4 20110101 20 2 The contract with greatest date being the active contract (don't blame me, I blame infor for creating xpps) I need to create query to see only active contracts (one contract per part, the contract with highest date). So the result of the query should be like this: contractId date price partId 1 20120121 10 1 3 20130101 15 2 I am out of ideas here, I tried self joining the table, I tried aggregation functions, but I can't figure it out. If anyone would have any idea, please share them with me..

    Read the article

  • Table alias -- Unkown column in field list

    - by Jason
    Hi all, I have a sql query which is executing a LEFT JOIN on 2 tables in which some of the columns are ambiguous. I can prefix the joined tables but when I try to prefix one of the columns from the table in the FROM clause, it tells me Unknown column. I even tried giving that table an alias like so ...From points AS p and using "p" to prefix the tables but that didn't work either. Can someone tell me what I'm doing wrong. Here is my query: SELECT point_title, point_url, address, city, state, zip_code, phone, `points`.`lat`, `points`.`longi`, featured, kmlno, image_url, category.title, category_id, point_id, lat, longi, reviews.star_points, reviews.review_id, count(reviews.point_id) as totals FROM (SELECT *, ( 3959 * acos( cos( radians('37.7717185') ) * cos( radians( lat ) ) * cos( radians( longi ) - radians('-122.4438929') ) + sin( radians('37.7717185') ) * sin( radians( lat ) ) ) ) AS distance FROM points HAVING distance < '25') as distResults LEFT JOIN category USING ( category_id ) LEFT JOIN reviews USING ( point_id ) WHERE (point_title LIKE '%Playgrounds%' OR category.title LIKE '%Playgrounds%') GROUP BY point_id ORDER BY totals DESC, distance LIMIT 0 , 10

    Read the article

  • PHP Export Date range

    - by menormedia
    I have a working database export to xls but I need it to export a particular date range based on the 'closed' date. (See code below). For example, I'd like it to export all 'closed' dates for last month and/or this month (Range: Sept 1, 2012 to Sept 30, 2012 or Oct 1, 2012 to Oct 31, 2012) <?PHP //EDIT YOUR MySQL Connection Info: $DB_Server = "localhost"; //your MySQL Server $DB_Username = "root"; //your MySQL User Name $DB_Password = ""; //your MySQL Password $DB_DBName = "ost_helpdesk"; //your MySQL Database Name $DB_TBLName = "ost_ticket"; //your MySQL Table Name //$DB_TBLName, $DB_DBName, may also be commented out & passed to the browser //as parameters in a query string, so that this code may be easily reused for //any MySQL table or any MySQL database on your server //DEFINE SQL QUERY: //edit this to suit your needs $sql = "Select ticketID, name, company, subject, closed from $DB_TBLName ORDER BY closed DESC"; //Optional: print out title to top of Excel or Word file with Timestamp //for when file was generated: //set $Use_Titel = 1 to generate title, 0 not to use title $Use_Title = 1; //define date for title: EDIT this to create the time-format you need $now_date = DATE('m-d-Y'); //define title for .doc or .xls file: EDIT this if you want $title = "MDT Database Dump For Table $DB_TBLName from Database $DB_DBName on $now_date"; /* Leave the connection info below as it is: just edit the above. (Editing of code past this point recommended only for advanced users.) */ //create MySQL connection $Connect = @MYSQL_CONNECT($DB_Server, $DB_Username, $DB_Password) or DIE("Couldn't connect to MySQL:<br>" . MYSQL_ERROR() . "<br>" . MYSQL_ERRNO()); //select database $Db = @MYSQL_SELECT_DB($DB_DBName, $Connect) or DIE("Couldn't select database:<br>" . MYSQL_ERROR(). "<br>" . MYSQL_ERRNO()); //execute query $result = @MYSQL_QUERY($sql,$Connect) or DIE("Couldn't execute query:<br>" . MYSQL_ERROR(). "<br>" . MYSQL_ERRNO()); //if this parameter is included ($w=1), file returned will be in word format ('.doc') //if parameter is not included, file returned will be in excel format ('.xls') IF (ISSET($w) && ($w==1)) { $file_type = "msword"; $file_ending = "doc"; }ELSE { $file_type = "vnd.ms-excel"; $file_ending = "xls"; } //header info for browser: determines file type ('.doc' or '.xls') HEADER("Content-Type: application/$file_type"); HEADER("Content-Disposition: attachment; filename=MDT_DB_$now_date.$file_ending"); HEADER("Pragma: no-cache"); HEADER("Expires: 0"); /* Start of Formatting for Word or Excel */ IF (ISSET($w) && ($w==1)) //check for $w again { /* FORMATTING FOR WORD DOCUMENTS ('.doc') */ //create title with timestamp: IF ($Use_Title == 1) { ECHO("$title\n\n"); } //define separator (defines columns in excel & tabs in word) $sep = "\n"; //new line character WHILE($row = MYSQL_FETCH_ROW($result)) { //set_time_limit(60); // HaRa $schema_insert = ""; FOR($j=0; $j<mysql_num_fields($result);$j++) { //define field names $field_name = MYSQL_FIELD_NAME($result,$j); //will show name of fields $schema_insert .= "$field_name:\t"; IF(!ISSET($row[$j])) { $schema_insert .= "NULL".$sep; } ELSEIF ($row[$j] != "") { $schema_insert .= "$row[$j]".$sep; } ELSE { $schema_insert .= "".$sep; } } $schema_insert = STR_REPLACE($sep."$", "", $schema_insert); $schema_insert .= "\t"; PRINT(TRIM($schema_insert)); //end of each mysql row //creates line to separate data from each MySQL table row PRINT "\n----------------------------------------------------\n"; } }ELSE{ /* FORMATTING FOR EXCEL DOCUMENTS ('.xls') */ //create title with timestamp: IF ($Use_Title == 1) { ECHO("$title\n"); } //define separator (defines columns in excel & tabs in word) $sep = "\t"; //tabbed character //start of printing column names as names of MySQL fields FOR ($i = 0; $i < MYSQL_NUM_FIELDS($result); $i++) { ECHO MYSQL_FIELD_NAME($result,$i) . "\t"; } PRINT("\n"); //end of printing column names //start while loop to get data WHILE($row = MYSQL_FETCH_ROW($result)) { //set_time_limit(60); // HaRa $schema_insert = ""; FOR($j=0; $j<mysql_num_fields($result);$j++) { IF(!ISSET($row[$j])) $schema_insert .= "NULL".$sep; ELSEIF ($row[$j] != "") $schema_insert .= "$row[$j]".$sep; ELSE $schema_insert .= "".$sep; } $schema_insert = STR_REPLACE($sep."$", "", $schema_insert); //this corrects output in excel when table fields contain \n or \r //these two characters are now replaced with a space $schema_insert = PREG_REPLACE("/\r\n|\n\r|\n|\r/", " ", $schema_insert); $schema_insert .= "\t"; PRINT(TRIM($schema_insert)); PRINT "\n"; } } ?>

    Read the article

  • MySQL select two tables at the same time...

    - by Jerry
    Hi all I have two tables and want to make a query. I tried to get team AA and team BB's image base on table A. I used: SELECT tableA.team1, tableA.team2, tableB.team, tableB.image, FROM tableA LEFT JOIN tableB ON tableA.team1=tableB.team The result only display imageA on the column. Are there any ways to select imageA and image B without using the second query? I appreciate any helps! Thanks a lot! My table structure are: table A team1 team2 ------------ AA BB table B team image ------------- AA imagaA BB imageB

    Read the article

  • How to order by results from 2 seperate tables in PHP and MySQL.

    - by Vafello
    I am trying to output results of 2 sql queries to one JSON file. The problem is that I would like to order them ascending by distance which is the result of equation that takes homelat and homelon from the users table and lat, lng from locations table.(basically it takes lattitude and longitude of one point and another and computes the distance between these points). Is it possible to take some parameters from both select queries, compute it and output the result in ascending order? $wynik = mysql_query("SELECT homelat, homelon FROM users WHERE guid='2'") or die(mysql_error()); ; $query = "SELECT * FROM locations WHERE timestamp"; $result = map_query($query); $points = array(); while ($aaa = mysql_fetch_assoc($wynik)) { while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { array_push($points, array('name'=>$row['name'], 'lat'=>$row['lat'], 'lng'=>$row['lng'], 'description'=>$row['description'], 'eventType'=>$row['eventType'], 'date'=>$row['date'], 'isotime'=>date('c', ($row['timestamp'])), 'homelat'=>$aaa['homelat'], 'homelon'=>$aaa['homelon'])); } echo json_encode(array("Locations"=>$points));

    Read the article

  • Accessing global variables within functions in PHP

    - by st3
    There are multiple times in one page where I need to connect and subsequently query a MySQL database, yet my code won't let me. I think it might be something to do with how my files are nested but it makes no sense. I am opening the SQL connection in the header file. The top of the offending page looks like the following: <?php $page_title = 'Dashboard'; include('templates/header.inc'); // includes a 'require_once('mysqli_connect.php') and a small query to the database; require_once('includes/functions.php'); require_once('includes/dashboard_sql.php'); // Contains functions which connect to database (which are failing.) ?> I get the PHP error Notice: Undefined variable: dbc in /Library/WebServer/Documents/pediatory_site/includes/dashboard_sql.php Where $dbc is the database connection defined in mysqli_connect.php. If anyone could help me out that would be great.

    Read the article

  • Display rows from MySQL where a datetime is within the next hour

    - by alex
    I always have trouble with complicated SQL queries. This is what I have $query = ' SELECT id, name, info, date_time FROM acms_events WHERE date_time = DATE_SUB(NOW(), INTERVAL 1 HOUR) AND active = 1 ORDER BY date_time ASC LIMIT 6 '; I want to get up to 6 rows that are upcoming within the hour. Is my query wrong? It does not seem to get events that are upcoming within the next hour when I test it. What is the correct syntax for this? Thanks

    Read the article

  • MySQL, return only rows where there are duplicates among two columns.

    - by Richard Waite
    I have a table in MySQL of contact information ; first name, last name, address, etc. I would like to run a query on this table that will return only rows with first and last name combinations which appear in the table more than once. I do not want to group the "duplicates" (which may only be duplicates of the first and last name, but not other information like address or birthdate) - I want to return all the "duplicate" rows so I can look over the results and determine if they are dupes or not. This seemed like it would be a simple thing to do, but it has not been. Every solution I can find either groups the dupes and gives me a count only (which is not useful for what I need to do with the results) or doesn't work at all. Is this kind of logic even possible in a query ? Should I try and do this in Python or something?

    Read the article

  • How to prompt user input parameters for SQL Queries in Access 2010

    - by user1848907
    SELECT Transactions.TransactionNumber FROM Transactions WHERE (((Transactions.Date)>=#11/23/12#)) AND (((Transactions.Date)<=#11/23/12#)); The above code returns all the transaction that happened between the specified dates. But I want those dates to be defined by the user every time the query is executed. I tried using the [] operators to have the user define the criteria in the WHERE, something like this: WHERE (((Transactions.Date)>=[Input a Date])) AND (((Transactions.Date)<=[Input a Date])); But microsoft Access throws a Syntax error message. The same happens when I include the # (date operators) like this WHERE (((Transactions.Date)>=#[Input a Date]#)) AND (((Transactions.Date)<=#[Input a Date]#)); Is there anopther way to manage dates that I'm not aware of or is asking a user for dates in a query out of the question

    Read the article

  • Techniques for querying a set of object in-memory in a Java application

    - by Edd Grant
    Hi All, We have a system which performs a 'coarse search' by invoking an interface on another system which returns a set of Java objects. Once we have received the search results I need to be able to further filter the resulting Java objects based on certain criteria describing the state of the attributes (e.g. from the initial objects return all objects where x.y z && a.b == c). The criteria used to filter the set of objects each time is partially user configurable, by this I mean that users will be able to select the values and ranges to match on but the attributes they can pick from will be a fixed set. The data sets are likely to contain <= 10,000 objects for each search. The search will be executed manually by the application user base probably no more than 2000 times a day (approx). It's probably worth mentioning that all the objects in the result set are known domain object classes which have Hibernate and JPA annotations describing their structure and relationship. Off the top of my head I can think of 3 ways of doing this: For each search persist the initial result set objects in our database, then use Hibernate to re-query them using the finer grained criteria. Use an in-memory Database (such as hsqldb?) to query and refine the initial result set. Write some custom code which iterates the initial result set and pulls out the desired records. Option 1 seems to involve a lot of toing and froing across a network to a physical Database (Oracle 10g) which might result in a lot of network and disk activity. It would also require the results from each search to be isolated from other result sets to ensure that different searches don't interfere with each other. Option 2 seems like a good idea in principle as it would allow me to do the finer query in memory and would not require the persistence of result data which would only be discarded after the search was complete. Gut feeling is that this could be pretty performant too but might result in larger memory overheads (which is fine as we can be pretty flexible on the amount of memory our JVM gets). Option 3 could be very performant but is something I would like to avoid as any code we write would require such careful testing that the time taken to acheive something flexible and robust enough would probably be prohibitive. I don't have time to prototype all 3 ideas so I am looking for comments people may have on the 3 options above, plus any further ideas I have not considered, to help me decide which idea might be most suitable. I'm currently leaning toward option 2 (in memory database) so would be keen to hear from people with experience of querying POJOs in memory too. Hopefully I have described the situation in enough detail but don't hesitate to ask if any further information is required to better understand the scenario. Cheers, Edd

    Read the article

< Previous Page | 136 137 138 139 140 141 142 143 144 145 146 147  | Next Page >