When used in the context of databases, memory refers to RAM directly addressable by the CPU as opposed to going through the I/O subsystem.

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18
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What is the default order of records for a SELECT statement in MySQL?

Suppose you have the following table and data: create table t(k int, v int,index k(k)) engine=memory; insert into t values(10, 1), (10, 2), (10, 3); When issuing select * from t where k = 10 with ...
8
votes
3answers
2k views

I am using the MEMORY storage engine but MySQL still writes to my disk…Why?

I am using the MEMORY Engine for all tables associated with a particular MYSQL query because speed of access is paramount to my project. For some reason, I have noticed that a large amount of disk ...
10
votes
5answers
62k views

Why is SQL Server consuming more server memory?

Sqlserver is consuming 87.5 % of my server Ram. This recently causes alot of performance bottleneck such as slowness.I Research on this issue. One common solution i could find on the internet is to ...
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 (...
6
votes
1answer
13k 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. It'...
14
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4answers
12k views

SQL Server Max Memory not limiting use of RAM

I would like your input on this. I have a sql server 2008r2 Ent. Ed. 64bit with 16 cores and 64GB RAM. There is one instance of SQL server patched fully as of 20111014. The max ram is set to 60000MB. ...
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 ...
6
votes
1answer
10k 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
4answers
9k views

MySQL gives “Out of Memory” error when inserting a large file. From where is this filesize limitation arising?

I'm using a MySQL database to store files. The table I'm using is structured as follows: +--------------+----------+------+-----+---------+-------+ | Field | Type | Null | Key | Default |...
1
vote
1answer
106 views

Adding new tables — memory usage increases

I added more tables to my mysql server. 20% increase in tables that are all innodb. I have 200 + databases that use the same schema. Does adding more tables increase memory usage? I am using about 1....
12
votes
3answers
8k views

SQL Server 2008 R2 “Ghost Memory”?

We have a dedicated SQL Server 2008 R2 machine that is experiencing some strange memory issues.. The machine itself has plenty of resources including two quad-core processors, 16gb of RAM and 64bit ...
7
votes
2answers
23k views

Quick look at how much RAM is allocated to SQL Server?

With SQL Server 2005, you could look at the Task Manager and, at least, get a cursory look at how much memory is allocated to SQL Server. With SQL Server 2008, the Working Set or Commit Size never ...
8
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3answers
5k views

ORA-04031: unable to allocate bytes of shared memory (“”,“”,“”,“”)

I am receiving this error in a development database. It happens on some specific queries (simple inserts and deletes via .NET application). The database is used by one user, and error happens ...
4
votes
4answers
2k views

Is it feasible to have MySQL in-memory storage engine utilize 512 GB of RAM?

I am considering scaling up instead of scaling out. Therefore, I am interested to hear whether it is feasible to utilize the MySQL in-memory storage engine for a database that is 500+ GB, given that ...
4
votes
2answers
11k views

Is InnoDB Engine up to speed against Memory Engine?

I am exploring the efficiency of different database engines in MySQL version 5.5.18 to see which is best suited for use with a range query on a dataset of 5 million rows: SELECT P.col1, P.col2, P....
4
votes
2answers
4k views

Microsoft SQL Server 2008 Memory

I am running MSSQL 2008 Enterprise and in the configuration of the server the Max memory amount is set to 2147483647 MB. My Question is, the server has 192 GB of ram,the number in the config can't be ...
2
votes
2answers
247 views

Do Inactive MySQL Databases Consume Memory?

I have inactive databases that are on the server just for archive purposes. I know I can do mysqldump for all of them, but I am not 100% sure they are inactive. When I started my system I didn't ...
8
votes
4answers
26k views

Why does MySQL say I'm out of memory?

I was trying to execute a fairly large INSERT...SELECT in MySQL with JDBC, and I got the following exception: Exception in thread "main" java.sql.SQLException: Out of memory (Needed 1073741824 bytes) ...
16
votes
2answers
34k views

How do I shrink the innodb file ibdata1 without dumping all databases?

InnoDB stores all tables in one big file ibdata1. After dropping a big table, the file is keeping its size no matter how big the table was. How can I shrink that file without having to dump and re-...
7
votes
2answers
20k views

SQL Server becomes slower over time until we have to restart it

We have a database with a mixed OLAP/OLTP workload. The queries are quite ad-hoc and are dynamically created in the mid-tier application server. When we start the server, the performance is quite ...
10
votes
2answers
21k views

Why is MySQL is creating so many temporary tables on disk?

Can any configuration mistake lead to creating too many temp tables by mysql..mysql tuner shows Current max_heap_table_size = 200 M Current tmp_table_size = 200 M Of 17158 temp tables, 30% were ...
7
votes
2answers
5k views

SQL Server 2012 memory consumption outside the buffer pool

I've got an instance of SQL Server 2012 SP2 Enterprise Edition consuming ~20GB of memory higher than the max. memory limit. The instance is limited to 65GB but the physical memory in use from the ...
9
votes
3answers
16k views

How to use insert delay with the InnoDB engine and use less connection for insert statements?

I'm working on an application which involves a lot of database writes, approximately ~70% inserts and 30% reads. This ratio would also include updates which I consider to be one read and one write. ...
4
votes
1answer
4k views

MySQL not releasing memory

MySQL seems to want to keep an entire table in cache (table size = ~20GB) after any large inserts or select statements are performed on it. Right now my innodb buffer pool is 20GB. Total RAM is 32GB. ...
7
votes
1answer
9k views

How do you increase MySQL performance using current server resources?

I have a MySQL database and some of my queries became slow. Query time is not stable. Most of the queries are fast, but some of them (may be that reads and returns less data) take long time. I know ...
3
votes
4answers
9k views

SQL Server 2008: how much RAM memory should SQL Server use in a 8GB RAM server?

We have SQL Server 2008 and 8GB RAM in a customer, hosted in a Windows 2008 R2 SP1, and consider the following amount of free memory: and consider the following running programs: Scenario: ...
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 ...
6
votes
3answers
5k views

How much memory will a MEMORY table take up?

Let's say I have a MyISAM table with a data length of 4.8GB and an index length of 6.2GB. So, a total data size of eleven gig. How much memory would this require, were I to convert it to a MEMORY ...
2
votes
3answers
41k views

SQL Server 2008 R2 High memory usage

I have SQL Server 2008 R2 that runs multiple jobs over night, the problem is SQL Server will eat up all RAM and CPU, then it will not release the RAM resources after the job finishes, as a workaround ...
2
votes
1answer
91 views

Troubleshooting memory pressure - how to avoid paging out SQL Server?

I have received the email below that states that an alert has been fired and a significant part of SQL Server process memory has been paged out should I raise the Minimum server memory to 1740 ...
8
votes
3answers
10k views

How to free SQL Server memory?

I have a SQL Server sandbox installation on my local computer. I have set the memory SQL Server instance can use to 1000 mb. When running an intensive operation, memory usage rises up to 1000 mb. When ...
4
votes
1answer
1k views

DB Engine Stolen Server Memory is too high

I get error from System Center Operations Manager (SCOM). How to solve this error? SQL DB 2012 Engine Stolen Server Memory is too high. I run query and get this counters: ╔════════════════════...
4
votes
2answers
3k views

SQL Server 2012 Standard Edition using more than 64GB of memory, why and how?

I put SQL Server 2012 Standard on a virtual machine (VMWare) which has roughly 98GB of Memory. Now I checked the query below how much memory is taken by SQL Server. Microsoft SQL Server 2012 - 11.0....
4
votes
2answers
6k views

Keeping default max memory 2147483647 MB value in SQL Server, a bad practice?

Based on that msdn page : server memory settings it's a good practice to keep the default values for SQL-Servers min and max memory to keep it dynamic... From what I learned through tutorials you ...
2
votes
3answers
733 views

RAM Impact on Oracle database operations

We are seeing drastic change in the amount of time taken for db operations depending on ram size. The same content when inserted into a db running on a 4gb ram machine takes about 600% more than into ...
16
votes
4answers
26k views

tuning postgresql for large amounts of ram

I have two identical servers (in terms of hardware), they are both standard installations of windows server 2008 r2, with minimal software installed (basically my code and required stuff like jvm etc)....
35
votes
4answers
4k views

On a dedicated database server, how much memory to reserve for the OS?

Assuming you have a dedicated server explicitly for database functions -- how much memory should you reserve for the operating system? I realize this will probably vary somewhat depending on the ...
21
votes
3answers
19k views

What are reasons *not* to use the MEMORY storage engine in MySQL?

I recently discovered that MySQL has a "memory" engine that I wasn't aware of (most of my database work is for hobby projects so I learn what I need as I go). It seems like this option should give me ...
31
votes
5answers
18k views

Why would I NOT use the SQL Server option “optimize for ad hoc workloads”?

I've been reading some great articles regarding SQL Server plan caching by Kimberly Tripp such as this one: http://www.sqlskills.com/blogs/kimberly/plan-cache-and-optimizing-for-adhoc-workloads/ Why ...
8
votes
4answers
5k views

MySQL Cluster RAM requirement

From MySQL 5.1, the data doesn't need to be entirely in memory anymore. I've read that the indexed columns (I think the entire index structure) must still be in memory (MySQL High Availability, 2010, ...
3
votes
1answer
9k views

Maximum possible memory usage: 16.2G (874% of installed RAM)

Why the MySQL is saying that can use about 16GB of RAM even if my server has only about 2GB? # ./mysqltuner.pl >> MySQLTuner 1.2.0 - Major Hayden <major@mhtx.net> >> Bug ...
7
votes
1answer
804 views

How much memory is a table taking up?

Is there a way to find out how much memory a table is taking up in SQL Server (2005 and greater)? For example, suppose I have a table with 30 million records. I'd like to know how many pages ...
7
votes
3answers
29k 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 ...
1
vote
2answers
3k views

Mysql Server 5.6 Mysqld high memory consumption

I have MySQL Server 5.6 installed in a development machine with these specs: RAM: 4 GB Windows 7 Professional 64 bits Intel Pentium CPU G630 @ 2.70 GHZ Since I installed the MySQL Server, the ...
1
vote
1answer
2k views

Can putting mysql DB into memory or having the innodb_buffer_pool_size match the size of DB increase performance?

We have a mysql database that has roughly 80 gigabytes (GB) of data using inno_db engine. We are looking to increase performance on the database (we looked at the slow log and gone through and ...
0
votes
1answer
384 views

How can lots of ram (128 GB) be used to improve MySQL 5.5 index creation?

This is similar to another post of mine, but now I have a different table structure, and it's still unclear what MySQL parameters should be changed to take advantage of the extra ram my machine has---...
6
votes
2answers
1k views

What does Page Life Expectancy say about the instance?

I have installed monitoring software on a few SQL Server instances in the environment. I am trying to find bottlenecks and fix some performance issues. I want to find out if some servers need more ...
5
votes
1answer
129 views

SSAS - what could be a good starting point for memory settings?

I have received the following alert regarding memory settings of SSAS: Alert: SSAS 2014: Invalid TotalMemoryLimit Configuration Source: MSSQLSERVER Path: SASBI01Alert time: 9/15/2015 5:38:50 PM ...
5
votes
2answers
585 views

Can I prove my database does not have memory issues?

(This is a continuation of do indexes consume memory) A fellow database developer believes we are having memory issues. He has seen increased run times in some standard queries - going from under 10 ...
2
votes
2answers
339 views

Is it possible for increasing the SQL Server max memory limit to degrade performance?

As far as I can tell, raising the SQL Server max memory limit has no drawbacks, provided that sufficient memory is left for the OS and other applications. Assuming this is the case, can there be any ...