Tables used to store transient data.

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2answers
740 views

Is a temporary table a good solution for importing temporary data into a database

i am facing the following scenario. I have a student database in which exam results are stored. Every now and then i get a list with the names of certain students for which i need to find out how well ...
4
votes
2answers
9k views

Are there advantages to using temporary tables over derived tables in SQL Server?

I read the derived tables have better performance than temporary tables, but anyway many SQL Server developers prefer the second ones. Why? I must do queries with large data (millions records) and I ...
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1answer
387 views

MySQL, temporary on disk table on primary key retrieval?

MySQL 5.5.24, Windows 7 64-bit. I've InnoDB table with primary key defined on three columns: CREATE TABLE `common_descriptions` ( `object_id` mediumint(8) unsigned NOT NULL DEFAULT '0', ...
0
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1answer
67 views

Optimize query to minimize tmp copying time

I have this mega query : SELECT s.eleve_id, crs.id_cours as 'cours_id', mc.code as cours_code, s.employe_id, s.id_seance, '0' as theorique, s.statut, s.type_vehicule_id, s.type_conduite_id, ...
7
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3answers
27k views

How long will a temporary MEMORY table persist if I don't drop it (MySQL)

I'm using a recursive stored procedure in MySQL to generate a temporary table called id_list, but I must use the results of that procedure in a follow up select query, so I can't DROP the temporary ...
0
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0answers
2k views

SQLite UPDATE two tables from VIEW or TEMPORARY TABLE

Here is the query that doesn't compile just to show how it should look like. But since I can't do Multiple table UPDATE's. This fake query should be able to run the inner UPDATE's for both tables if ...
0
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2answers
720 views

table does not exist

CREATE OR REPLACE PROCEDURE ProcedureX() TYPE AVERAGE_COUNT_TBL IS TABLE OF INTEGER; AVERAGE_COUNT AVERAGE_COUNT_TBL; BEGIN INSERT INTO AVERAGE_COUNT VALUES(10); END ProcedureX; It ...
1
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1answer
168 views

How big is a tmp table?

I've got an RDF table in MySQL 5.1 with the MyISAM engine. Here's the table definition: CREATE TABLE `node` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `graph` varchar(100) CHARACTER SET latin1 ...
0
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1answer
197 views

MySQL thread states when changing an in-memory temporary table to disk-based

In High Performance MySQL (3rd edition) they state that: You can't tell whether a table was created in memory and then converted to on-disk or just created on-disk to begin with... What I was ...
15
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2answers
39k views

MySQL creates temporary tables on disk. How do I stop it?

We are running a site (Moodle) that the users currently find slow. I think I have tracked down the problem to MySQL creating temporary tables on disk. I watch the variable created_tmp_disk_tables in ...
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2answers
1k views

Should I load the data into Temp table or keep calling it from the normal table? [closed]

I am writing a procedure and find myself using the same select statement with the same where clause a lot. Currently the table holds over 55000 rows and grows about 100 or so rows each day. The two ...
2
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2answers
2k views

if block fails to create temp table in a procedure

I'm attempting to do this in a procedure: DECLARE @a bit = 1; BEGIN SELECT * INTO #aTemp FROM OPENROWSET( ... ); IF @a = 0 BEGIN SELECT ... INTO #bTemp FROM #aTemp; END ...
2
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2answers
2k views

changing TEMPORARY TABLE default collation

when I use CREATE TEMPORARY TABLE to create a temporary table, the collation of this table is utf8_unicode_ci by default. why by default it is utf8_unicode_ci? How can I change the default?
1
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1answer
1k views

Can I remove #sql_ .MYD files?

I found some old files in the mysql datadir: -rw-rw---- 1 mysql mysql 0 2012-10-09 09:39 #sql_263c_0.MYD -rw-rw---- 1 mysql mysql 1.0K 2012-10-09 09:39 #sql_263c_0.MYI -rw-rw---- 1 mysql ...
0
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3answers
3k views

Creating a global temp table in MySQL

I am working on a MySQL stored procedure. I need to create a temp table and I want to access this temp table whenever I execute this stored procedure. I know we can't access the temp table in ...
1
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2answers
751 views

What is the size of currently-existing tmp tables in innodb?

This is yet another "how to add a column to a gigantic table" question. The table on disk takes 2.5GB, and I have around 10GB of ram I can use. I have a feeling I can crank up the tmptablesize option ...
4
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2answers
5k views

Can I copy the table structure of a #temp table to a new physical table?

I have a #tempTable that was created using SELECT * INTO #tempTable FROM OPENROWSET('Microsoft.Ace.OLEDB.12.0', 'Excel 8.0;Database=MyFileName.xls', 'SELECT * FROM [Sheet1$]') Is there an easy way ...
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0answers
140 views

Why is this query creating 300+ temporary tables in Mysql?

SHOW global STATUS LIKE '%tmp%'; set @UID = 132; set @param2 = 'cde'; set @param3 = 20130331; set @param4 = 'C'; select p.id, p.column44, p.column42, ue.column35, u.id, p.column43, p.column45, ...
4
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1answer
29k views

temporary table inside procedure oracle

I'm in a situation right now. I'm migrating several procedures from Mysql 5.0 to Oracle 11g. Mysql procedures allow me to: 1. Create temporary tables 2. Insert data into temporary tables / Query these ...
4
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1answer
5k views

How to get a list of global temporary tables in the current database?

I am trying to get a list of the global temporary tables that are currently active. There seems to be an issue with them bumping in to each other (same name). As the 'acting' dba, trying to sort out a ...
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0answers
147 views

TMD auto create

I used mysql as part of a project and found it to be a very practical tool. I have a question about mysql in regards to how it creates temporary table types TMD in /var/lib/mysql/. This partition ...
5
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1answer
4k views

Is there a MySQL engine or trick to avoid writing so many temp tables to disk?

I've got a web application connected to a database running MySQL. Here's the problem: a not insignificant number of queries create temporary tables and many of the tables involved have BLOB fields. ...
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2answers
495 views

Size of TempDB Microsoft SQL Server 2005

Are there drawbacks to having a large tempdb in a SQL Server database? Assuming the disk is not full. I am creating large temporary tables in a couple of queries. Once I am finished running queries, ...
5
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3answers
14k views

Why does MySQL produce so many temporary MYD files?

On a Debian Linux server, hosting many PHP/MySQL websites (photo galleries), sometimes I have "many" files like /tmp/#sql_6405_58.MYD. For example today : [2012-12-15 15:18:11] /tmp/#sql_6405_6.MYD ...
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0answers
69 views

Map records to a time interval

I have two tables: SamplesTbl contains samples every 5 seconds of a bike ride RxTbl contains the prescribed stages and other values of a bike ride SamplesTbl SamplesID int SessionNum int StageNum ...
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1answer
252 views

Binding errors with dependent stored procedures

We are getting strange errors on one of our stored procedures. This stored procedure calls other stored procedures & we are getting errors relating to columns that cannot be found in the sub ...
7
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2answers
6k views

Is it bad to create many mysql temporary tables simultaneously?

I need to make heavy statistical analysis to deliver some data to users. Currently, I catch the data from mysql and process them via PHP arrays. However, mysql temporary tables are quite better ...
1
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2answers
164 views

SQL 2008 RTM Temp Tables

Today I implemented a monitoring solution on our SQL server using Cacti and the first thing i noticed is the growth in the number of temporary tables, in just 3 hours on our test system we had an ...
15
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2answers
2k views

Does varchar size matter in temporary tables?

There is a debate at my wife's work about just using varchar(255) for all varchar fields in temporary tables in stored procedures. Basically, one camp wants to use 255 because it will always work ...
3
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1answer
25k views

MySQL: Execute CREATE TEMPORARY TABLE SELECT just one time?

I want to create a temporary table with some select-data. My (strange) problem is that I have to do the same query more than one time. CREATE TEMPORARY TABLE IF NOT EXISTS cache (id int(11) NOT ...
1
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1answer
917 views

Inserting query result to another table hangs on “Copying to temp table on disk” on MySQL

I started the process of inserting returned results to another table. The query groups the rows in respect of indexed IDs. This causes 149,000,000 rows to be decreased to 460,000 rows. The query ...
2
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1answer
2k views

How to handle temporary tables with mutliple connections?

In Is there a way to hint to query optimizer to mysql which contraints should be done first? I created a subquery. The subquery is often not optimized. I think a better way is to create a temporary ...
2
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0answers
488 views

Why are runtimes different for a table including a primary key versus a table with a clustered unique index added after population [closed]

When I create a temporary table with a PK defined from the outset like this I get great performance in subsequent joins on that key: create table #temp ( field1 int not null field2 int ...
2
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2answers
3k views

mysql 5.5 corrupt - missing temporary table

One of our mysql instances crashed and failed to start: 120422 10:04:13 InnoDB: Error: trying to open a table, but could not InnoDB: open the tablespace file './databasename/#sql-29f6_45.ibd'! ...
1
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1answer
153 views

Should I use table hints with a process-keyed table?

I read on stackoverflow that locking can be a problem when using process-keyed tables, and I was wondering if you had any suggestions on how to minimize or avoid unnecessary contention (e.g. table ...
298
votes
3answers
134k views

What's the difference between a temp table and table variable in SQL Server?

This seems to be an area with quite a few myths and conflicting views. So what is the difference between a table variable and a local temporary table in SQL Server?
12
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2answers
7k views

INSERT performance difference between temporary tables and table variable

I have the following issue in SQL Server 2005: trying to inserts some rows into a table variable takes a lot of time compared to the same insert using a temporary table. This is the code to insert ...
26
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1answer
8k views

Why is using a table variable more than twice as fast as a #temp table in this specific case?

I was looking at the article here Temporary Tables vs. Table Variables and Their Effect on SQL Server Performance and on SQL Server 2008 was able to reproduce similar results to those shown there for ...
2
votes
1answer
4k views

Repairing Myisam Table when there was no additional Disk space & Table corrupted

I had a table which MyIsam as storage Engine contains million rows. There is a purging task and need to remove 35 days old data. i measured up the rows in following manner : mysql> select ...
6
votes
3answers
973 views

Why is @temp table performance some times worse than #temp table performance?

I was recently working in a very slow stored procedure (took 5 minutes to run). I made a very small tweak from doing this: declare @tempTable table ( ... ) insert into @tempTable select ..... to ...
2
votes
2answers
583 views

What reason is there to create a physical table for a report output?

I've noticed that for Crystal Reports made by our organization and by some of our ERA software providers have a tendency to use physical tables for their reports' data sets, rather than using a view ...
1
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3answers
6k views

ON DUPLICATE KEY UPDATE question

I'm trying to compare data from two systems. The basic idea is: Create Temp Table. Insert Table1 Data. Insert Table2 data (Table a linked, remote server) with UNIQUE Ids respected. Filter where ...
4
votes
1answer
851 views

What are all the reasons/possibilities that may fail to release disk space occupied by TEMPORARY table?

We're using PostgreSQL v8.2.3. Ours is a web-based application and we're using pgpool-II v 2.0.1 purely for connection pooling (we don't use other features of pgpool like Replication, Load Balancing, ...
6
votes
1answer
832 views

Guarantee SQL Server Identity Columns that two consecutive values differ by constant increments?

I posed a question about Denali sequences here and another question about emulation of identity columns in Oracle Global Tables here. I always thought that I could trust that identity values ...
1
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1answer
582 views

Performance problem caused by joining with the result of a scalar function?

In the following example the performance of the first version using only one SQL query is very bad. The problem is the last join. When I store the result of the left side into a temporary table and ...
7
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1answer
513 views

Dealing with temp tables when I have not control over db variables

I have no control over things like tmp_table_size and max_heap_table_size, and so as our tables grow the time taken by queries requiring temp tables is growing geometrically. I am wondering if there ...