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.
1
vote
2answers
57 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
3answers
660 views
Memory problems with MySQLWorkbench
I'm currently using MySQLWorkbench 5.2.40 on my PC (8GB rRM, Corei7). I have a table with almost 1.5 million records, which I need to visually look over. Surprisingly, the total size does not exceed ...
4
votes
3answers
107 views
How to see what is cached in memory in SQL server 2008?
Is there a way how to find out what is cached in SQL Server 2008 R2? I have found the following nice article: ...
1
vote
1answer
67 views
Does DBMS (e.g. of SQL SERVER 2008) use virtual memory?
Or in other words ... . Does the DBMS somehow circumvent the OS Cache manager and acccess the memory directly OR it lets the OS do its job, behave as a normal process and use the concept of virtual ...
3
votes
0answers
50 views
What are reasonable options for an in-memory multi-core database?
I'm going to preface this with pointing out that I only need somewhat persistent data. The purpose of this database platform would be to support statistical analysis in R. I usually build my tables ...
0
votes
1answer
29 views
Does MySQL reserve memory for MEMORY tables based on max_heap_table_size
Currently I have a set of large MEMORY tables, and have previously calculated how much space I believe each will require and assigned max_heap_table_size accordingly so that the sum is not greater ...
3
votes
3answers
4k 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
2answers
112 views
Total Memory capped far below available memory
We are testing out a new install of SQL Server 2012 on a virtual server and the memory allocated to SQL Server seems to be capped around 16 GB even though much more is available. What could cause ...
3
votes
2answers
6k 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 ...
3
votes
1answer
78 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 ...
1
vote
1answer
85 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
0answers
34 views
What value should oracle.install.db.config.starterdb.memoryLimit be set to in the Oracle response file for a silent installation?
What happens when oracle.install.db.config.starterdb.memoryLimit is not set in the Oracle response file for a silent installation?
I noticed that when recording the response file for a silent Oracle ...
0
votes
0answers
86 views
SQL Server Internal Memory Pressure
I am trying to identify the cause of internal memory pressure. From what I have learned, Resource Monitor Ring Buffer returns an indicator for internal pressure. For example by using this query,
...
1
vote
2answers
31 views
how to know how many instances of an application are running on server
I've solaris server running many applications, using Oracle.
I want to know how many different databases are running within Oracle, and how much memory and cpu each of them is consuming
4
votes
3answers
256 views
Unable to start Oracle (11g1) due to bad memory configuration (ORA-00837)
I decided to reduce the memory allocation of a local developer instance, and was told that the following command did the job;
alter system set memory_max_target = 512M scope = spfile;
Which I guess ...
13
votes
4answers
544 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 ...
5
votes
2answers
727 views
SQL Server gets slow 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 ...
3
votes
4answers
273 views
Stress Test to Saturate Memory for MySQL InnoDB
I'm investigating windows 32bit memory problems (the 2G limit) and am after a test which will max out MySQL's memory including InnoDB Buffer Pool, per connection memory and/or any other uses of ...
3
votes
1answer
107 views
Can memcached improve performance for InnoDB in mem with a large innodb_buffer_pool_size?
I learned that innodb_buffer_pool_size makes innodb behave like an in memory db. If I give innodb_buffer_pool_size enough ram for the entire db could memcached improve further the performance, or ...
4
votes
2answers
100 views
How to properly configure PostgreSQL RAM usage?
Using PostgreSQL, we have several hundred concurrent processes doing regular database access. We have our data spread out through several database servers, each of which houses a connection pool with ...
1
vote
2answers
200 views
How should I tune Postgresql for 20 GB of RAM?
I've been fortunate enough to have the use of a 20GB Linode instance running Ubuntu 64 bit. I want to try to optimize PostGres for this service, but I don't know what I should prioritize changing.
I ...
10
votes
5answers
3k views
PostgreSQL: Force data into memory
Is there a systematic way to force PostgreSQL to load a specific table into memory, or at least read it from disk so that it will be cached by the system?
2
votes
0answers
205 views
“custom archiver out of memory” error when restoring large DB using pg_restore
I'm trying to a restore a local copy of a 30GB DB (with only one table) dumped using the Heroku wrappers (described here) using pg_restore. The Heroku DB is using 9.1.7 and I have had the same result ...
0
votes
2answers
828 views
NoSQL, CouchDB vs. CouchBase, What should i do?
I started to encounter some issues on my production site, when having a web page that needs to load a very big ResultSet (currently coming from relational database, MySQL) it takes forever, and ...
2
votes
2answers
199 views
Minimum/Maximum Server Memory in SQL Server 2005 with /3GB and /Userva switches
I have a 32-Bit Windows 2003 machine with 3.75GB RAM running one SQL Server 2005 instance. I am trying to optimize memory. If I use the switches in boot.ini like below,
/3GB /Userva=2490
should I ...
0
votes
1answer
127 views
memcached service stopped unexpectedly
I am working with
MySQL Cluster 7.2.4
memcached 1.6
I started memcached service with ndb-caching option:
memcached -E /usr/local/mysql/lib/ndb_engine.so -e ...
-1
votes
2answers
174 views
SQL Server Express - Memory limitation vs. web application [closed]
I have web application that will be similar to forums. I plan to have thousands of users on this application, and I wonder if I can use SQL Server Express.
Here is the list of it's limitations:
...
7
votes
2answers
326 views
Increased RAM, Worse Performance
Setup:
Windows Server 2008 R2
SQL Server 2008 R2 SP1
240GB RAM
TempDB is 8x16GB data files w/out auto-grow (128GB total)
Physical/Stand-alone Server
This server is used for ETL processing. We ...
3
votes
4answers
3k 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 ...
3
votes
2answers
552 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 ...
4
votes
2answers
4k 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 ...
25
votes
3answers
2k 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 ...
0
votes
1answer
121 views
Why doesn't more memory necessarily make Postgres more performant?
The Postgres resource consumption docs state, under the shared_buffers:
...it is unlikely that an allocation of more than 40% of RAM to shared_buffers will work better than a smaller amount.
Why ...
3
votes
1answer
259 views
MongoDB Not Using All Available RAM
I have something around 200 GB worth data stored in a mongo cluster. The physical memory on one of the instances which runs mongo is 8GB. Nothing else of any consequence runs on this instance. As near ...
19
votes
3answers
4k views
Is the SQL Server Express memory and CPU limit per instance?
If I have 8GB of RAM in a server and I run 4 instances of SQL Server Express, will the total memory limit used by SQL Server be 1GB or 4GB?
Would it be advisable to run multiple instances like this ...
1
vote
0answers
40 views
memcached+mysql cluster maximum memory
I'm deploying a system with memcached and mysql cluster.
The command line is:
memcached -E lib/ndb_engine.so -e "connectstring=maddy:1186;role=dev"
I can't specify the -m argument since I used -E ...
14
votes
3answers
19k views
Recommended page file size for SQL 2008R2 on Windows 2008R2
This Microsoft article - How to determine the appropriate page file size for 64-bit versions of Windows Server 2008 and or Windows 2008 R2 provides guidance for calculating the page file size for 64 ...
4
votes
1answer
264 views
SQL Server Buffer Pool Utilization under VMWare
I recently migrated a physical SQL Server box (2012) over to ESX (5.1) simply for ease of administration. It is and will be the only guest on the server. As expected there was a marginal performance ...
2
votes
2answers
84 views
Sql Server memory issue
As soon as i start SQL Server with no application querying ,in the task manager it starts to consume memory very fast till it consumes around 15GB.
Can any one tell me how to resolve this issue.
...
1
vote
1answer
94 views
Why does a MySQL MEMORY-backed table take so much more space than on disk?
I have a single InnoDB table on disk, with ~1,107,423 rows and taking up 45.6 MiB disk space. The structure is:
messageid int(11)
signature varchar(255)
When I create a MEMORY-backed version of ...
10
votes
1answer
486 views
SQL Server - Anyone use SUMA, trace flag 8048, or trace flag 8015?
Recently included SQL Server startup Trace Flag 8048 to resolve a serious spinlock contention issue in a SQL Server 2008 R2 system.
Interested to hear from others who have found usage cases where ...
1
vote
1answer
500 views
MongoDB: What does '[DataFileSync] flushing mmaps took … ms for … files' mean?
I am building an index in MongoDB for a large collections (~300GB) and the db terminal window keeps printing:
[DataFileSync] flushing mmaps took 10920ms for 151 files
The time that it takes to ...
2
votes
2answers
2k views
mysql out of available memory
We have a dedicated MySQL server with 16GB of RAM that's serving 8 web workers with relatively high traffic (over 1000 requests per second at peak traffic)
At peak we're seeing the following errors ...
2
votes
0answers
148 views
PostgreSQL 9.2.1 out of memory on \COPY
I'm running a postgreSQL 9.2.1 installation in a FreeBSD 9.0 Jail with default settings.
I've configured loader.conf according to this post: ...
0
votes
2answers
408 views
MySQL how to release memory used up by SELECT
I executed an INSERT IGNORE combined with SELECT from large table. The SELECT took up 16GB of memory and went into SWAP before I terminated it with CTRL+C.
INSERT IGNORE INTO sid(sid)
SELECT sid ...
1
vote
1answer
550 views
SSIS: “The buffer manager cannot write 8 bytes to file”
We have about 60 or more SSAS cubes on one server. All the cubes have the same structure. Each cube has a different size because each cube has a different underlying data warehouse. However the schema ...
3
votes
1answer
241 views
PostgreSQL memory spike upgrade from 8.2 to 9.1
We recently upgraded a few of our development computers from PostgreSQL 8.2 to 9.1, with plans on eventually upgrading our production servers. Everything seems well with the restore of the databases, ...
0
votes
2answers
64 views
MySQL still holding memory after I shut it down?
I used this command to shutdown MySQL, however it seems the amount of free memory on my box has not changed?
That seems to odd.
/usr/local/webserver/mysql/bin/mysqladmin -u ${mysql_username} ...
5
votes
4answers
7k 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)
...
0
votes
0answers
267 views
Potential cause for memory leak
I have a replication setup where one of those nodes started experiences a slow but steady memory leak.
The setup is kind of like this
M---->S
|
\/
FilteringSlave
| | | |
R1 R2 R3 ...
