Search Results

Search found 33585 results on 1344 pages for 'sql execution plan'.

Page 682/1344 | < Previous Page | 678 679 680 681 682 683 684 685 686 687 688 689  | Next Page >

• Is a primary key automatically an index?

  - by Lieven Cardoen

  If I run Profiler, then it suggests a lot of indexes like this one CREATE CLUSTERED INDEX [_dta_index_Users_c_9_292912115__K1] ON [dbo].[Users] ( [UserId] ASC )WITH (SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF) ON [PRIMARY] UserId is the primary key of the table Users. Is this index better than the one already in the table: ALTER TABLE [dbo].[Users] ADD CONSTRAINT [PK_Users] PRIMARY KEY NONCLUSTERED ( [UserId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

  Read the article

• How to join two query in SQL (Oracle)

  - by MAHESH A SONI

  How can I join these queries? SELECT RCTDT, SUM(RCTAMOUNT), COUNT(RCTAMOUNT) FROM RECEIPTS4 WHERE RCTDT BETWEEN '01-nov-2009' AND '30-nov-2009' AND RCTTYPE='CA' AND RCTAMOUNT>0 GROUP BY RCTDT --- SELECT RCTDT, SUM(RCTAMOUNT), COUNT(RCTAMOUNT) FROM RECEIPTS4 WHERE RCTDT BETWEEN '01-nov-2009' AND '30-nov-2009' AND RCTTYPE='CQ' AND RCTAMOUNT>0 GROUP BY RCTDT

  Read the article

• Multiple ID's in database

  - by eric

  I have a database that contains a few tables such as person, staff, member, and supporter. The person table contains information about every staff, member, and supporter. The information it contains is name,address,email, and telephone. I also created an id that is the primary key. My issue is that I also have an primary key ID for staff, member, and supporter. For instance, in the person table is John with id 1. He is a supporter so in the supporter table is pID(for person id)to reference back to John with all his information and ID(for supporter ID). pID references to the person table and every person has an ID incremented by 1 starting at 1. supporter ID is for every supporter and also starts at 1 and is incremented by 1. Is it possible to have in the supporter table pID = 1 and supporter ID = 1? Another person may have a pID = 26 and supporter ID = 5. Or will supporter ID have to be different than the pID and be something like "sup"? So you would have pID = 1 and supporter ID = sup1 or pID = 26 and supporter ID = sup5

  Read the article

• Get count matches in query on large table very slow

  - by Roy Roes

  I have a mysql table "items" with 2 integer fields: seid and tiid The table has about 35000000 records, so it's very large. seid tiid ----------- 1 1 2 2 2 3 2 4 3 4 4 1 4 2 The table has a primary key on both fields, an index on seid and an index on tiid. Someone types in 1 or more tiid values and now I would like to get the seid with most results. For example when someone types 1,2,3, I would like to get seid 2 and 4 as result. They both have 2 matches on the tiid values. My query so far: SELECT COUNT(*) as c, seid FROM items WHERE tiid IN (1,2,3) GROUP BY seid HAVING c = (SELECT COUNT(*) as c, seid FROM items WHERE tiid IN (1,2,3) GROUP BY seid ORDER BY c DESC LIMIT 1) But this query is extremly slow, because of the large table. Does anyone know how to construct a better query for this purpose?

  Read the article

• How can I get all children from a parent row in the same table?

  - by Johnny Freeman

  Let's say I have a table called my_table that looks like this: id | name | parent_id 1 | Row 1 | NULL 2 | Row 2 | NULL 3 | Row 3 | 1 4 | Row 4 | 1 5 | Row 5 | NULL 6 | Row 6 | NULL 7 | Row 7 | 8 8 | Row 8 | NULL 9 | Row 9 | 4 10 | Row 10 | 4 Basically I want my final array in PHP to look like this: Array ( [0] => Array ( [name] => Row 1 [children] => Array ( [0] => Array ( [name] => Row 3 [children] => ) [1] => Array ( [name] => Row 4 [children] => Array ( [0] => Array ( [name] => Row 9 [children] => ) [1] => Array ( [name] => Row 10 [children] => ) ) ) ) ) [1] => Array ( [name] => Row 2 [children] => ) [2] => Array ( [name] => Row 5 [children] => ) [3] => Array ( [name] => Row 6 [children] => ) [4] => Array ( [name] => Row 8 [children] => Array ( [0] => Array ( [name] => Row 7 [children] => ) ) ) ) So, I want it to get all of the rows where parent_id is null, then find all nested children recursively. Now here's the part that I'm having trouble with: How can this be done with 1 call to the database? I'm sure I could do it with a simple select statement and then have PHP make the array look like this but I'm hoping this can be done with some kind of fancy db joining or something like that. Any takers?

  Read the article

• Which MySql line is faster:

  - by Camran

  I have a classified_id variable which matches one document in a MySql table. I am currently fetching the information about that one record like this: SELECT * FROM table WHERE table.classified_id = $classified_id I wonder if there is a faster approach, for example like this: SELECT 1 FROM table WHERE table.classified_id = $classified_id Wont the last one only select 1 record, which is exactly what I need, so that it doesn't have to scan the entire table but instead stops searching for records after 1 is found? Or am I dreaming this? Thanks

  Read the article

• Has anyone ever successfully make index merge work for MySQL?

  - by user198729

  Setup: mysql> create table t(a integer unsigned,b integer unsigned); mysql> insert into t(a,b) values (1,2),(1,3),(2,4); mysql> create index i_t_a on t(a); mysql> create index i_t_b on t(b); mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 3 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Is there something I'm missing? Update mysql> explain select * from t where a=1 or b=4; +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | t | ALL | i_t_a,i_t_b | NULL | NULL | NULL | 1863 | Using where | +----+-------------+-------+------+---------------+------+---------+------+------+-------------+ Version: mysql> select version(); +----------------------+ | version() | +----------------------+ | 5.1.36-community-log | +----------------------+ Has anyone ever successfully make index merge work for MySQL? I'll be glad to see successful stories here:)

  Read the article

• Count total number of callers?

  - by Kristopher Ives

  I'm currently doing this query to find the guy who makes the most calls: SELECT `commenter_name`, COUNT(*) AS `calls` FROM `comments` GROUP BY `commenter_name` ORDER BY `calls` LIMIT 1 What I want now is to be able to find out how many total unique callers. I tried using DISTINCT but I didn't get anywhere.

  Read the article

• Getting "too many rows" error inside a "for" cursor loop

  - by Will

  I have a trigger that contains two cursors loops, one nested inside the other like this: FOR outer_rec IN outer_cursor LOOP FOR inner_rec IN inner_cursor LOOP -- Do some calculations END LOOP; END LOOP; Somewhere in this it is throwing the following error: ORA-01422: exact fetch returns more than requested number of rows I've been trying to determine where it's coming from for an hour or so.. but should this error never happen? Also.. I am assuming the inner loop automatically closes and opens itself again every time the outer loop goes the next record, i hope this is correct.

  Read the article

• MYSQL count all rows per table for in one query

  - by Lee

  Is there a way to query the DB to find out how many rows there are in all the tables ie table1 1234 table2 222 table3 7888 Hope you can advise

  Read the article

• running a stored procedure inside a sql trigger

  - by Ying

  Hi all, the business logic in my application requires me to insert a row in table X when a row is inserted in table Y. Furthermore, it should only do it between specific times(which I have to query another table for). I have considered running a script every 5 minutes or so to check this, but I stumbled upon triggers and figured this might be a better way to do it. But I find the syntax for procedures a little bewildering and I keep getting an error I have no idea how to fix. Here is where I start: CREATE TRIGGER reservation_auto_reply AFTER INSERT ON reservation FOR EACH ROW BEGIN IF NEW.sent_type = 1 /* In-App */ THEN INSERT INTO `messagehistory` (`trip`, `fk`, `sent_time`, `status`, `message_type`, `message`) VALUES (NEW.trip, NEW.psk, 'NOW()', 'submitted', 4, 'This is an automated reply to reservation'); END; I get an error in the VALUES part of the statmenet but im not sure where. I still have to query the other table for the information I need, but I can't even get past this part. Any help is appreciated, including links to many examples..Thanks

  Read the article

• ms-access: difference between control source and row source

  - by every_answer_gets_a_point

  i have learning reports in access and i don't understand the difference between these two concepts. i understand that the control source is the column? but then what is the row source?

  Read the article

• 2-column table with two foreign keys. Performance/design question.

  - by Emanuel

  Hello everyone! I recently ran into a quite complex problem and after looking around a lot I couldn't find a solution to it. I've found answers to my questions many times before on stackoverflow.com, so I decided to post here. So I'm making a user/group managment system for a web-based project, and I'm storing all related data into a postgreSQL database. This system relies on three tables: USERS GROUPS GROUP_USERS The two first tables simply define all the users and all the groups on the site, and the last table, GROUP_USERS, stores the groups every user is part of. It only has two columns: USER_ID GROUP_ID Since every user can be a member of several groups, I decided to make a separate table for this purpose, rather than storing a comma separated column in the USERS-table. Now, both columns are foreign keys, and I want to make them both primary keys as well, this since each combination of USER_ID and GROUP_ID has to be unique, and if I give them the constraint UNIQUE pgAdmin tells me that each table should have at least one Primary key. But now I am stuck with what seems to be a lot of indexes and relations to a very small table only containing numbers. In the end, I want this table to be as fast as possible, even if containing tens of thousands of rows. Size on disk shouldn't be a problem since its just all numbers anyway, but it feels quite stupid to have a full-sized index refering to a smaller table. Should I stick with my current solution, store comma-separated values in a column in the USERS-table or is there any other solution I should be aware of. PS. I don't want to use an array-column, even if they are supported by postgreSQL. I want to be as generic as possible so I can switch database later on, if necessary. EDIT: I other words, will using a compound primary key and two foreign keys in one table with only two columns have a negative impact on performance rather than the opposite due to the size of the generated index? Thank you!

  Read the article

• Microsoft Sync Framework with Sync Services for ADO.NET - how does it scale?

  - by dbruning

  We are about to embark on a major project which requires an Occasionally Connected Application. The MS Sync Framework seems to offer a good solution with Sync Services for ADO.NET. Has anyone used this in a production app, ideally with tens of thousands of users, and can you comment on how well it scales? Any other pitfalls or gotcha's? Thanks!

  Read the article

• error in fill datagrid whit query

  - by Amir Tavakoli

  i have a data-gride-view and i add my query to this when write my query i catch this error: The schema returned by the new query differs from the base query and this my query: SELECT B.SettingKey, 'SysSettingsDep' AS TableName, B.SettingValue, B.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettingsDep AS B ON A.SettingKey = B.SettingKey UNION SELECT C.SettingKey, 'SysSettingsMachine' AS TableName, C.SettingValue, C.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettingsMachine AS C ON A.SettingKey = C.SettingKey UNION SELECT D.SettingKey, 'SysSettings' AS TableName, D.SettingValue, D.SettingDesc FROM SysCustomer AS A INNER JOIN SysSettings AS D ON A.SettingKey = D.SettingKey help me to solve this, tnx

  Read the article

• MySQL "NULL" questions

  - by Camran

  I have a table with several columns. Sometimes some of these column fields may be empty (ie. I won't use them in some cases). My questions: Would it be smart to set them to NULL in phpmyadmin? What does the "NULL" property actually do? Would I gain anything at all by setting them to NULL? Is it possible to use a NULL field the same way even though it is set to null?

  Read the article

• Calculating percent of votes inside mysql statement.

  - by Beck

  UPDATE polls_options SET `votes`=`votes`+1, `percent`=ROUND((`votes`+1) / (SELECT voters FROM polls WHERE poll_id=? LIMIT 1) * 100,1) WHERE option_id=? AND poll_id=? Don't have table data yet, to test it properly. :) And by the way, in what type % integers should be stored in database? Thanks for the help!

  Read the article

• .Net 3.5 - SQL : Compatibility issues. Changing attributes automatic

  - by krishnanunni

  I would like to make notice of some wierd thing. I designed an entire package application using VB.Net in Visual Studio 2008. I changed the normal backgrounds to Black, to make a diffrerence. but the problem is i1mm getting changing back ground colors when i install it on other systems.which does have all supports required. What should i do to supress this problem.

  Read the article

• PreparedStatement.setString() method without quotes

  - by Slavko

  I'm trying to use a PreparedStatement with code similar to this: SELECT * FROM ? WHERE name = ? Obviously, what happens when I use setString() to set the table and name field is this: SELECT * FROM 'my_table' WHERE name = 'whatever' and the query doesn't work. Is there a way to set the String without quotes so the line looks like this: SELECT * FROM my_table WHERE name = 'whatever' or should I just give it up and use the regular Statement instead (the arguments come from another part of the system, neither of those is entered by a user)?

  Read the article

• Concurrent usage of table causing issues

  - by Sven

  Hello In our current project we are interfacing with a third party data provider. They need to insert data in a table of ours. This inserting can be frequent every 1 min, every 5min, every 30, depends on the amount of new data they need to provide. The use the isolation level read committed. On our end we have an application, windows service, that calls a webservice every 2 minutes to see if there is new data in this table. Our isolation level is repeatable read. We retrieve the records and update a column on these rows. Now the problem is that sometimes this third party provider needs to insert a lot of data, let's say 5000 records. They do this per transaction (5rows per transaction), but they don't close the connection. They do one transaction and then the next untill all records are inserted. This caused issues for our process, we receive a timeout. If this goes on for a long time the database get's completely unstable. For instance, they maybe stopped, but the table somehow still stays unavailable. When I try to do a select on the table, I get several records but at a certain moment I don't get any response anymore. It just says retrieving data but nothing comes anymore until I get a timeout exception. Only solution is to restart the database and then I see the other records. How can we solve this. What is the ideal isolation level setting in this scenario?

  Read the article

• History tables pros, cons and gotchas - using triggers, sproc or at application level.

  - by Nathan W

  I am currently playing around with the idea of having history tables for some of my tables in my database. Basically I have the main table and a copy of that table with a modified date and an action column to store what action was preformed eg Update,Delete and Insert. So far I can think of three different places that you can do the history table work. Triggers on the main table for update, insert and delete. (Database) Stored procedures. (Database) Application layer. (Application) My main question is, what are the pros, cons and gotchas of doing the work in each of these layers. One advantage I can think of by using the triggers way is that integrity is always maintained no matter what program is implmentated on top of the database.

  Read the article

• Getting the last element of a Postgres array, declaratively

  - by Wojciech Kaczmarek

  How to obtain the last element of the array in Postgres? I need to do it declaratively as I want to use it as a ORDER BY criteria. I wouldn't want to create a special PGSQL function for it, the less changes to the database the better in this case. In fact, what I want to do is to sort by the last word of a specific column containing multiple words. Changing the model is not an option here. In other words, I want to push Ruby's sort_by {|x| x.split[-1]} into the database level. I can split a value into array of words with Postgres string_to_array or regexp_split_to_array functions, then how to get its last element?

  Read the article

• Get previous and next row from current id

  - by Hukr

  How can I do to get the next row in a table? `image_id` int(11) NOT NULL auto_increment `image_title` varchar(255) NOT NULL `image_text` mediumtext NOT NULL `image_date` datetime NOT NULL `image_filename` varchar(255) NOT NULL If the current image is 3 for example and the next one is 7 etc. this won’t work: $query = mysql_query("SELECT * FROM images WHERE image_id = ".intval($_GET['id'])); echo $_GET['id']+1; How should I do? thanks

  Read the article

• Embedded Java Databases for Large Data Sets

  - by ExAmerican

  I would like to port a PHP/MySQL-based client/server application to be a standalone desktop application written in Java. The database has grown to be fairly large, with several tables with hundreds of thousands of rows. I expect these could grow to over a million entries for certain tables. What embedded database would best handle this? HSQLDB and Sqlite seem to be the obvious choices, though I'm guessing there are others out there as well. My main priorities are the ability to perform queries on large amounts of data efficiently (this thread seems to confirm Sqlite can handle this) and the ease with which I can import old data from MySQL (I remember HSQLDB being kind of a pain for that). Note: I am aware that similar questions comparing embedded databases have been posted before (for example here and here) but as my priorities differ somewhat from most applications considering the large data migration I thought it justified a new question.

  Read the article

• Optimize SQL query (Facebook-like application)

  - by fabriciols

  My application is similar to Facebook, and I'm trying to optimize the query that get user records. The user records are that he as src ou dst. The src is in usermuralentry directly, the dst list are in usermuralentry_user. So, a entry can have one src and many dst. I have those tables: mysql> desc usermuralentry ; +-----------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+------------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | user_src_id | int(11) | NO | MUL | NULL | | | private | tinyint(1) | NO | | NULL | | | content | longtext | NO | | NULL | | | date | datetime | NO | | NULL | | | last_update | datetime | NO | | NULL | | +-----------------+------------------+------+-----+---------+----------------+ 10 rows in set (0.10 sec) mysql> desc usermuralentry_user ; +-------------------+---------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------------+---------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | usermuralentry_id | int(11) | NO | MUL | NULL | | | userinfo_id | int(11) | NO | MUL | NULL | | +-------------------+---------+------+-----+---------+----------------+ 3 rows in set (0.00 sec) And the following query to retrieve information from two users. mysql> explain SELECT * FROM usermuralentry AS a , usermuralentry_user AS b WHERE a.user_src_id IN ( 1, 2 ) OR ( a.id = b.usermuralentry_id AND b.userinfo_id IN ( 1, 2 ) ); +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ | 1 | SIMPLE | b | ALL | usermuralentry_id,usermuralentry_user_bcd7114e,usermuralentry_user_6b192ca7 | NULL | NULL | NULL | 147188 | | | 1 | SIMPLE | a | ALL | PRIMARY | NULL | NULL | NULL | 1371289 | Range checked for each record (index map: 0x1) | +----+-------------+-------+------+-------------------------------------------------------------------------------------------+------+---------+------+---------+------------------------------------------------+ 2 rows in set (0.00 sec) but it is taking A LOT of time... Some tips to optimize? Can the table schema be better in my application?

  Read the article

< Previous Page | 678 679 680 681 682 683 684 685 686 687 688 689  | Next Page >