Database Administrators Stack Exchange
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1500 questions
21
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2 answers

How to determine MySQL queries per day?

I'm investigating the big switch from MySQL to a NoSQL DBaaS and I've run into an issue trying to forecast expenses. Essentially, I can't figure out how many queries my current MySQL server handles per day to try and estimate the number of requests…
AJB
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Is there a way to access temporary tables of other sessions in postgres?

I'm working with a Windows application that uses a (local) postgres Database and stores some information in a temporary table. I'd like to have a look at the temporary table, but pgadmin and dbVis tell me: ERROR: cannot access temporary tables of…
newenglander
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5 answers

Is ROLLBACK a fast operation?

Is it true that RDBMS systems are optimized for COMMIT operations? How much slower/faster are ROLLBACK operations and why?
garik
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21
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5 answers

SQL Server Database Not Shrinking

I have an SQL Database with a lot of unused space. However when I run Tasks | Shrink | Database And Tasks | Shrink | Files from Management studio it isn't freeing up any space. Unfortunately the machine that it is running on is running out of hard…
DermFrench
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21
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2 answers

What is blocking and how does it happen?

I tried to find some information about blocking in SQL Server, but I could not find a concise explanation for what it is and how it happens. Could you please enlighten me?
jrara
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21
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4 answers

What does "index" mean on RDBMSs?

I use indexes like most developpers do (mostly on... well ! index), but i'm sure there is a lot of subtle way to optimize a database using index. I'm not sure if it is specific to any implementation of a DBMS. My question is : what are good examples…
Thomas Joulin
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3 answers

What max_allowed_packet is big enough, and why do I need to change it?

I have MySQL (5.5) in master-slave setup and created another slave server. I stopped the original slave, dumped the data, copied and reimported and it worked fine. I noted the master_log pos of the original slave and used these commands to set it on…
CodeMonkey
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21
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2 answers

Connection pools being reset with Error: 18056, Severity: 20, State: 46. & Perfmon Counters not showing

We are using SQL Authentication (to reduce the number of connection pools) & .NET 4.0 connection strings to connect to SQL Server Enterprise Edition 2012 SP1 on a Windows 2008 R2 Enterprise Server: Microsoft SQL Server 2012 (SP1) - 11.0.3000.0…
DamagedGoods
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21
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4 answers

How to list all postgres tables in one particular schema

Using the psql command line tool, how do I list all postgres tables in one particular schema
user23593
21
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3 answers

Is it possible to get execution call stack in a trigger?

I have 10 stored procedures and each of them does INSERTs into one tableX. Is it possible in a trigger body of tableX to get what object causes modification of tableX (stored proc1 or sp2 or....) ? Thank you.
garik
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21
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3 answers

SQL Server Restore a SINGLE table from a backup

on SQL Server 2005, we do a weekly full backup with nightly incremental backups. I want to know if it is possible to restore a single table from a backup, either to the source database or a different one. I can not find any clear answer online.…
GWR
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1 answer

Should I be alarmed by this NO JOIN PREDICATE warning?

I'm troubleshooting the bits and pieces of a poorly-performing stored procedure. This section of the procedure is throwing a NO JOIN PREDICATE warning select method = case methoddescription when 'blah' then 'Ethylene…
swasheck
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21
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4 answers

Can I change the SID of an Oracle database?

The Server is Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Is there an easy & quick way to change the SIDs of the test databases on the server? Dropping & recreating of the database is an option for me. But I'm looking for…
bernd_k
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1 answer

Why is my ORDER BY in STRING_AGG not always working?

I have a table that consists of a record ID, a group ID (linking 1 or more records into a group) and a hash value for each record. CREATE TABLE HashTable( RecordID VARCHAR(255), GroupIdentifier VARCHAR(255), Hash VARCHAR (255), …
Rebecca
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21
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3 answers

PostgreSQL: Can I do pg_start_backup() on a live, running db under load?

Our established replication has broken ("requested WAL segment has already been removed" during downtime) We cannot easily stop the master again. Can we do pg_start_backup(), rsync ${PGDATA}/ master to slave, pg_stop_backup() ... while the…
Daniel
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