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8
votes
4answers
18k views

Making sense of INNODB buffer pool stats

After having read this page in the mysql documentation, I tried to make sense of our current InnoDB usage. Currently, we allocate 6GB of RAM for the buffer pool. Our database size is about the same. ...
7
votes
2answers
226 views

Microsoft SQL Server 2012 Mirrors Go Into Disconnected

I have some Microsoft SQL server 2012 mirrors, without a witness in asynchronous mode, that are sporadically going into disconnected. I am running SQL Server 2012 11.0.5058. Looking at the logs on ...
6
votes
4answers
482 views

How can I Debug a Buffer Issue?

I have a production "Microsoft SQL Server 2012 (SP1) - 11.0.3128.0 (X64)" that is showing weird buffer and page life expectancy (PLE) symptoms. I am running this every minute on my server (to track ...
5
votes
2answers
209 views

Buffer Size Changing?

I have a production database that is experiencing wildly fluctuating Page Life Expectancy (PLE) issues. (It crashes to zero at random times.) I have been researching the PLE issue and have found ...
5
votes
3answers
4k views

Optimal Number of MySQL InnoDB Buffer Pool Instances

Server Characteristics Total system RAM: 8GB (running MySQL + other stuff than MySQL on it i.e. not dedicated to MySQL) Number of CPU Cores: 6 I have data in the db amounting to about 2GB I have ...
4
votes
1answer
381 views

Buffer usage for index with no reads

Using SQL Server 2008 R2, the main transactional table in a vendor database is massive compared to all others and has about 14 indexes. Some of these indexes don't get used in our environment, but we ...
4
votes
2answers
372 views

Is it a waste to set innodb_buffer_pool_instances greater than the # of CPUs?

I set the innodb_buffer_pool_size to 20GB on a server with 12 CPU cores. My full database is 11gb, however most of it is archived tables that are almost never used. The total queried data is around 3 ...
3
votes
2answers
215 views

optimal size of innodb buffer pool

I read a lot of optimal number of innodb_buffer_pool_size and people say it must be larger with 10% than the innodb tables size, what is 60M. Accordyngly this the optimal size of the buffer is about ...
3
votes
1answer
2k views

dbcc memorystatus - buffer pool target on VM higher than max memory

I'm doing some digging into potential memory/configuration problems on a sql server 2012 SP2. I stumbled upon something that seems a bit strange in the performance counters as well as the dbcc ...
3
votes
1answer
3k views

Finding swap causes of MySQL

In my centos 6.3 server I have a MySQL 5.5.33 database. It has 17 tables (15 InnoDB, 2 MyISAM) and total records 6.7M rows. I refactored my schemas and added indexes for my slow logs. My average query ...
2
votes
2answers
183 views

Sudden MySQL freeze, with spike in dirty pages, but without obvious write queries

I'm systematically (1/2 times per day) experiencing a freeze in the DB server. Suddenly, all the COMMITs get stuck in 'init' state; they pile up (up to 20/30), an almost no other queries are executed ...
2
votes
1answer
2k views

InnoDB Buffer Pool Hit Rate

As given at http://cherry.world.edoors.com/COBFKUqnUdBY one can obtain buffer hit ratio by following sql query: SELECT round ((P2.variable_value / P1.variable_value),4), P2.variable_value, P1....
2
votes
2answers
2k views

Why would increase in innodb_buffer_pool_size slow down MySQL?

5.1.68-cll - MySQL Community Server on CentOS The system has 32GB of RAM. I increased innodb_buffer_pool_size from 10240M to 15360M (10GB -> 15GB). Time taken for a series of identical operations ...
2
votes
1answer
66 views

InnoDB buffer pool active pages

I'd like to optimize (lower) the InnoDB buffer pool size. How can one find out how many distinct pages are active in the InnoDB buffer pool? A page could be made young twice in a while (see SHOW ...
2
votes
1answer
2k views

How to create Buffer Pool in Database dedicated only for ONE BIG table?

I have table TICKET with 400K records in database (DB2). I wish to create one huge buffer pool which will be dedicated only to this one big table for faster response. What are the steps to do it? ...
2
votes
0answers
352 views

Empty Space in buffer pool

I was doing some reading and came across this article from Paul Randal: http://www.sqlskills.com/blogs/paul/performance-issues-from-wasted-buffer-pool-memory/ Using the queries from that article, I ...
2
votes
0answers
281 views

tempdb objects creator wanted, bufferpool issue caused by tempdb objects

I have a number of tables in tempdb named like #A0030B77 #A01D908C #A06D1FCB #A0F72FB0 #A1614404 #A1EB53E9 #A205D8FE #A255683D How (if) can I get spid of the process which created them? These ...
1
vote
3answers
303 views

Will redirecting queries to dev/null warm up indexes?

I'm trying to warm up the buffer pool. Will running a query and re-directing the output to /dev/null suffice? e.g. mysql -u username -p -e "select id from tbl where 1=1" > /tmp/results.txt Thanks
1
vote
2answers
886 views

MySQL stores BLOB in innodb buffer pool (innodb_buffer_pool_size)?

I have several databases all in INNODB, 50GB are BLOB columns, only 700MB are not BLOB data. Tools as mysqltuner ask me to set innodb_buffer_pool_size = 51GB. Does MySQL store the BLOB in RAM? If yes,...
1
vote
1answer
489 views

In Sql Server what is the difference between VAS and Buffer Pool?

My understanding: In Sql Server, Buffer Pool is where all the Data/Proc/Log Cache, etc are located. Virtual Address Space is a logical location that refers to physical locations (either in RAM or ...
1
vote
1answer
57 views

Does InnoDB Log Files take RAM space or Disk Space

When I set InnoDB Log File size to 512M, does it take the space (512M * 2) from RAM or the SSD Disk space? When I explored, I can see that the log files are located inside /var/lib/mysql folder. So ...
1
vote
1answer
30 views

“Approximately equal” between Sync and Async operations for PageCleaners

The documentation of num_iocleaners says: The parameter can be reduced if both of the following conditions are true: pool_data_writes is approximately equal to pool_async_data_writes ...
1
vote
1answer
404 views

Should indexes automatically be placed into their own bufferpool?

We work with DB2 LUW (specifically we are currently on 9.7 FP4) running on AIX. Per best practices from IBM, they recommend that when you build a table, you place the data, the indexes, and LOBs/LONG ...
1
vote
1answer
538 views

mysql innodb_buffer_pool_size let me understand

I couldn't find answer for my situation. I have a windows server 2008 with 2 cores and 7 GB RAM (Azure D1 VM). I'm running mariadb 10.0.14 on it. I have 2 databases (1.5GB and 9GB in size). ...
1
vote
0answers
131 views

Does “CREATE INDEX WITH DROP_EXISTING” use the bufferpool for the recreated index?

We have recreate our 4TB clustered index in ouor SQL Server. Even thought we have 1.5TB of memory we still run into the following error message: "Msg 802, Level 17, State 2, Line 30 There is ...
1
vote
0answers
36 views

AlwaysOn AG Live Migration

A couple of thoughts on AlwaysOn AG migrations: Is there a reason why Microsoft didn't implement similar technology to Hyper-V Live Migration to AlwaysOn AGs so that the buffer pool and cache are ...
1
vote
2answers
13k views

How to set Innodb Buffer Pool Size [duplicate]

I have a database using innodb completely. Its now having a innodb_buffer_pool_size at 128MB. Which I know is very less for my user. But no matter what I do it won't change. I have added a value of ...
0
votes
1answer
1k views

DB2 - How to estimate proper BUFFERPOOL size?

DB2 9.7. 8GB RAM on server. Currently BP has 500 MB (number of pages*pagesize) Database has issue with increased IOPS. So we think maybe BP should be increased. How to estimate needed size for BP? Is ...
0
votes
2answers
45 views

MySql not using Buffer Pool

I'm checking into a buffer pool issue on a MySql database. According to the query to get database size shown here, the total database size is about 11GB. Unfortunately I know I have much less RAM than ...
0
votes
1answer
106 views

memory leaks in innodb

I have MySQL server 5.6 and I use stress test to evaluate the performance of it. after the test the result of mysqltuner.pl was like below : root@master-1:/home/debian# perl mysqltuner.pl Please ...
0
votes
1answer
50 views

Does innodb_data_reads include reads from the buffer pool?

We have set up some monitoring on many of our databases that serve many different applications. It seems that they all report back more writes than reads when in reality that is very unlikely. I ...
0
votes
1answer
2k views

DB2 LUW: Should temporary tablespaces share bufferpools with other tablespaces?

We are in the process of tuning a massive application our company has just written. Part of that tuning includes tuning the databases. We run DB2 LUW on AIX. Specifically we are at 9.7 Fix Pack 4 (...
0
votes
0answers
6 views

1K unused pages in each InnoDB buffer pool instance

I have configured a InnoDB buffer pool of 12 Gb, split into a dozen instances 1 Gb each. The buffer pool hit rate is 1000 / 1000, therefore so far it's looking good. Looking at the stats of the ...
0
votes
0answers
4 views

Different innodb_buffer_pool usage in nodes of a cluster

I have a 3-nodes Percona XtraDB Cluster (MySQL 5.6) that was put into operation three weeks ago. I noticed that the innodb_buffer_pool usage is very different in each of the nodes. In node #1, usage ...
0
votes
1answer
77 views

MySQL 5.7 not accepting values of innodb_buffer_pool_instances greater than 1

I've been tweaking the values of the buffer pool size (innodb_buffer_pool_size) and the number of buffer pool instances (innodb_buffer_pool_instances) in the my.ini initialization file to optimize ...
0
votes
0answers
245 views

Should innodb_buffer_pool_size be much larger than the innodb_buffer_pool_bytes_data?

Our old server had 32GB total RAM, 18GB allocated to innodb_buffer_pool_size. It also had 10GB for the php_memory_limit. The new one had 16GB RAM, 9GB for innodb, 5GB for php. The same application ...