8
votes
2answers
4k views

Any gotchas at all with converting from MyISAM to InnoDB?

I'm ready to move from MyISAM to InnoDB but wanted to know if there was a full list of things to look for? For example, I haven't seen any list mention that running DISABLE KEYS on an InnoDB table ...
16
votes
2answers
877 views

Decision criteria on when to use a non-dbo schema vs a new Database

I'm mostly an application developer but find myself having to do all the up-front database work for my current project (btw... its MS SQL Server 2008). As a first decision, I'm trying to figure out ...
4
votes
2answers
3k views

MySQL on SSD - what are the disadvantages? [closed]

Recently, I heard that I should not host my MySQL database on an SSD drive because there is a big chance of disk failure and data lost. Given that 20% of all queries in my database are INSERTs and ...
12
votes
2answers
1k views

Postgres query plan of a UDF invocation written in pgpsql

It's possible when using the pgadmin or plsql to get a hold of a query plan for a sql statement executed via a UDF (using EXPLAIN). So, how do I get a hold of the query plan for a particular ...
10
votes
4answers
12k views

Audit logins on MySQL database

Is there a way to audit logins to MySQL? I'd like to be able to create a username for each employee and thereby create an audit trail of logins. However, googling has turned up no good results. The ...
7
votes
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 ...
7
votes
2answers
5k views

Is this a normal set of MySQL privileges?

Using phpmyadmin on a local test wamp setup, and well as pretty much the title states, there are 3 users marked as user = ANY, password = NO, such as: USER | HOST | Password | Global Priv | Grant ...
4
votes
3answers
4k views

MySQL slow log configuration

Is there a way of making MySQL slow logs to start new log file every day ? At the moment its just a single large file, and have to grep lines for every day. It would be much more convenient to have ...
5
votes
1answer
2k views

Which mysql storage engine to choose?

I'm confused about which mysql engine should I choose (lets talk about the most used : MyISAM and InnoDB). The theories say: Both work with BTree indexes, but MyISAM can work with FULLTEXT index ...
4
votes
2answers
2k views

Run a PowerShell script on a different server - from inside a SQL Server job

I have a procedure to backup SSAS Databases. That is working as a charm. Now my server is filling up with SSAS backups and I would like to delete the backup files that are older than 2 days. to ...
3
votes
2answers
2k views

How do I determine how much data is being written per day through insert, update and delete operations?

The longevity of SSDs is largely determined by the amount of bytes written by insert, update and delete operations. What is the best way to accurately determine how much data is being written by ...
3
votes
1answer
5k views

gain admin access to sql express 2008

I have inherited a Windows 7 Professional pc with an existing instance of SQL Express 2008. I have local admin rights on the machine. I do not know the SA password. I am unable to create databases or ...
2
votes
1answer
3k views

MySQL upgrade 5.0.88 to latest

Very interesting and informative blog.. I have a question - i have a requirement of upgrading from 5.0.88 to latest version.. Why should i upgrade? if so, which version should i consider? What ...
5
votes
1answer
675 views

“Site Offline” MySQL server failing to start and stop

I'm hosting a few sites on linode and have encountered a strange problem. For the last two years the site has been running perfectly fine, and now randomly all the websites on the server go to the ...
5
votes
2answers
8k views

How to refresh AD security group on Sql Server permissions

I am using Sql Server 2008 on Small Business Server 2003; client is using WinXP. I added a user to my Active Directory Security Group; Why can't this user immediately access the database? It seems ...
5
votes
3answers
5k views

Why is SSMS inserting new rows at the top of a table not the bottom?

Whenever I manually insert a row into a table in SQL Server Management Studio 2008 (the database is SQL Server 2005) my new row appears at the TOP of the list rather than the bottom. I'm using ...
3
votes
1answer
153 views

Constrains relationship

I have the following design. Each user has it's own contacts, it's own hosts and assign those to a domain which belongs only to him. I want to insure that the host you assign to the domain belongs ...
1
vote
1answer
5k views

ERROR 1114 (HY000) at line 6308 in file & The table user_analysis is full

There is a SAN mounted 1TB partition for Mysql backups in our server with version 5.0.45-log. From two days, im seeing the log entries ERROR 1114 (HY000) at line 6308 in file & The table ...
47
votes
6answers
43k views

What are the main causes of deadlocks and can they be prevented?

Recently one of our ASP.NET applications displayed a database deadlock error and I was requested to check and fix the error. I managed to find the cause of the deadlock was a stored procedure that was ...
80
votes
5answers
27k views

When should I use a unique constraint instead of a unique index?

When I want a column to have distinct values, I can either use a constraint create table t1( id int primary key, code varchar(10) unique NULL ); go or I can use a unique index create table t2( id ...
32
votes
3answers
12k views

Parameter Sniffing vs VARIABLES vs Recompile vs OPTIMIZE FOR UNKNOWN

So we had a long running proc causing problems this morning (30 sec + run time). We decided to check to see if parameter sniffing was to blame. So, we rewrote the proc and set the incoming ...
32
votes
1answer
43k views

intermittent MySQL crashes with error “Fatal error: cannot allocate memory for the buffer pool”

Added on edit, 2013-05-29: Because this is a long question and discussion, here's a short summary of the question and the solution. I had problems running MySQL and Apache on a small Linux server (1 ...
26
votes
3answers
28k views

How to turn json array into postgres array?

I have a field user that holds a json document that roughly looks like that: { name: 'foo', tags: ['foo', 'bar'] } I would like to turn the tags array into a concatenated string (foo, bar). ...
17
votes
7answers
50k views

Need to migrate SQL Server to MySQL

I have a database on SQL Server 2008 on a Windows server and I want to move all of the data to a MySQL database on a Ubuntu server. I have tried using the SQL Server Import and Export Wizard with the ...
18
votes
6answers
3k views

Needing A Database Design Book

I am designing a database and it has so many relationships among my tables and i need a book that teaches database design very well.I am looking for a book where table relationships simple and complex ...
21
votes
4answers
9k views

Using SQL Profiler on a database that's in production

As a developer, I use SQL Profiler quite often. It's a good debugging tool, both to track what my code is doing and to analyse performance problems. But I've always used it on my development ...
8
votes
1answer
5k views

Qcache_free_memory not full yet I get alot of Qcache_lowmem_prunes

I just started dabbling with the query cache for our CMS. Can anyone tell me (or at least give a good guess) why I get a lot of Qcache_lowmem_prunes when more than half of Qcache_free_memory is free? ...
4
votes
1answer
3k views

Proper tuning for 30GB InnoDB table on server with 48GB RAM

I have a 30GB 15M rows InnoDB MySQL 5.5.15 table. It is running on a server with many other MyISAM tables (300GB db). The system has 48GB RAM. Besides the default configurations, I've changed the ...
15
votes
2answers
2k views

What can we do in MySQL 5.0 Replication to address bandwidth concerns?

I am developing an application to run on the client PC (Win) which is configured with a MySQL server 5.1 instance that will act as read-only slave to the remote master. The remote master has dozens of ...
9
votes
2answers
6k views

How to create an Event Notification that runs a Job/procedure when mirroring state changes

I'm asking this question in the sequence of this one Can I send a string over TCP using T-SQL? Remus Rusanu exposes what it seems to be an optimal solution for my problem, but... I'm too immature to ...
6
votes
5answers
52k views

List all permissions for a given role?

I've searched around all over and haven't found a conclusive answer to this question. I need a script that can give ALL permissions for an associated role. Any thoughts, or is it even possible? ...
6
votes
1answer
6k views

Best solution for cross-datacenter MySQL master-slave replication

We are working on a new system architecture for our company. We have a HPC, which runs in our own data-center and we are planning our front-end and a fallback system on Amazon Web Service. System ...
4
votes
1answer
3k views

Mysql Memory table getting many locks

On my site I log every pageview (date, ip, referrer, page, etc) in a simple mysql table. This table has the following activity: 1 SELECT per minute 1 DELETE per minute no UPDATE queries Lots of ...
17
votes
3answers
16k views

Is it possible to restore sql-server bak and shrink the log at the same time?

We have a bak file from a client that we have transferred to our developer offices for problem investigation. The backup is currently 25GB and the restored database is about the same size however it ...
5
votes
2answers
5k views

When should I think about upgrading our RDS MySQL instance based on memory usage?

It seems like our DB server is doing garbage collection at a increasingly faster rate, which seem normal since it's growing. What's a good rule of thumb of when to switch to a bigger instance, I'm not ...
9
votes
3answers
15k views

How do you re-sync the Master MySQL DB with Slave DB changes if the Master goes offline?

MySQL Server 1 is running as Master. MySQL Server 2 is running as Slave. With both DBs online, they are in "perfect sync". If Slave goes offline, there's no problem if Master still online; they will ...
5
votes
1answer
828 views

Should I use a storage engine other than MyISAM to optimise these tables or should I get better disks?

There's a production database I'm working on, whose 4 largest tables contain between 4 million and 10 million rows each and about 15 fields each, with indexes on different field types (numbers, ...
4
votes
4answers
12k views

Optimized my.cnf for high-end and busy server

Curretly my main culprit of poor performance is MySQL and I'm not a DB savvy. So far, I've had little luck in optimizing mysql configs on my server, which has a Sandy Bridge processor with 16GB ram ...
14
votes
2answers
15k views

Why index REBUILD does not reduce index fragmentatation?

I have used ALTER INDEX REBUILD to remove index fragmentation. In some cases REBUILD does not seem to remove this fragmentation. What are the reasons why REBUILD does not remove fragmentation? It ...
11
votes
2answers
12k views

Need to understand parallel query execution error

Today we experienced a degradation in performance on our production sql server. Durring the time this occurred we logged several "The query processor could not start the necessary thread resources ...
9
votes
2answers
6k views

ETL: extracting from 200 tables - SSIS data flow or custom T-SQL?

Based on my analysis, a complete dimensional model for our data warehouse will require extraction from over 200 source tables. Some of these tables will be extracted as part of an incremental load and ...
6
votes
1answer
9k views

SQL Server - How to determine ideal memory for instance?

We have some virtual machines that have X memory allocated to them. This amount of memory is somewhat random. It was allocated to the machine because that was the amount of memory the physical ...
6
votes
2answers
3k views

Insert-heavy InnoDB table won't use all my CPU

I have a packet log database, which is almost never queried. It just needs to be fast on inserts. I'm using InnoDB because I'd like to maintain ACID compliance, since even losing a single packet could ...
5
votes
1answer
12k views

SQL Server Maximum and Minimum memory configuration

What are the correct settings for min-memory and max-memory in this use case? The server has 8GB ram, dual Intel Xeon processors, running Windows Server 2008 R2 / Sql Server 2008 Standard Edition. ...
5
votes
3answers
7k views

Disable trigger for just one table

Is it possible to disable a trigger momentarily but for just one table. For example I have table, TableA with an on insert, update and delete trigger. I also have a table B with the same triggers but ...
4
votes
3answers
2k views

Log MySQL DB changing queries and users

For security reasons I need a server-side (running Debian 6.0 Squeeze) logging of all queries that may have changed the content of a MySQL DB (v. 5.1) and the user who issued it. I had to rule out ...
4
votes
2answers
9k views

MySQL Event does not run

i am running mysql 5.1.41 that came bundled with xampp on windows. the problem is that the event doesnt run automatically even when the event scheduler is ON. i have a table named ta_table using ...
2
votes
1answer
7k views

Any known issues upgrading from MySQL 5.1.73 to 5.6.21?

I am planning my MySQL DB ver5.1.73 running on a CentOS 6.5 machine to MySQL 5.6.21. I understand the basic procedure for this based on what I have read on StackOverflow, but I was curious if anyone ...
8
votes
4answers
42k views

Call a stored procedure from a trigger

I have created a stored procedure in mysql using the following syntax. DROP PROCEDURE IF EXISTS `sp-set_comment_count`; DELIMITER $$ CREATE PROCEDURE `sp_set-comment_count` (IN _id INT) BEGIN -- ...
7
votes
2answers
5k views

How do I determine if a column is defined as a serial data type instead of an integer based off the catalog?

So I'm currently creating some SQL to read through the postgres (9.1) catalogs to build table definitions. However, I am encountering a problem with SERIAL/BIGSERIAL data types. Example: CREATE ...

15 30 50 per page