{"id":321,"date":"2009-12-18T06:04:50","date_gmt":"2009-12-18T00:34:50","guid":{"rendered":"http:\/\/kedar.nitty-witty.com\/?p=321"},"modified":"2023-06-10T09:33:52","modified_gmt":"2023-06-10T09:33:52","slug":"mysql-memory-usage-limits-on-32-bit-linux-os","status":"publish","type":"post","link":"https:\/\/kedar.nitty-witty.com\/blog\/mysql-memory-usage-limits-on-32-bit-linux-os","title":{"rendered":"MySQL Memory Usage Limits on 32 bit Linux"},"content":{"rendered":"\n

I\u2019m having RHEL 5 (32-bit) and MySQL-5.<\/p>\n\n\n\n

I was trying to check how much is the Memory Utilization limits for MySQL 5 on 32bit OS.<\/p>\n\n\n\n

We can easily calculate the maximum capacity of the address space is 2^32 bytes and that is where these limits come from.
* For MYSQL 5.0: Following are memory (storage) limits:<\/strong><\/p>\n\n\n\n

Max DB size:  Unlimited
Max table size:  MyISAM: 256TB; Innodb: 64TB
Max row size: 64 KB
Max columns per row: 4096
Max Blob\/Clob size: 4 GB (longtext, longblob)
Max CHAR size: 64 KB (text)
Max NUMBER size: 64 bits
Min DATE value: 1000
Max DATE value: 9999
Max column name size: 64<\/p>\n\n\n\n

* OS Memory Limitations:<\/strong><\/p>\n\n\n\n

Maximum x86 per-process virtual address space for Red-Hat Linux Version
Version 4: ~ 4GB
Version 5: ~ 3GB
* Server Parameters memory allocation limits:
<\/strong>
For following buffers:
\u2022 key_buffer_size
\u2022 join_buffer_size
\u2022 myisam_sort_buffer_size
\u2022 sort_buffer_size
– Maximum allowable setting is 4GB.
– As of MySQL 5.1.23, values larger than 4GB are allowed for 64-bit platforms.<\/p>\n\n\n\n

Others:
net_buffer_length -1MB.
read_buffer_size – 2GB.
read_rnd_buffer_size – 2GB.<\/p>\n\n\n\n

* About globally limiting memory usage by MySQL Server:
<\/strong>
MySQL is not having any other parameter that directly limits the memory usage. It\u2019s these global buffers \/ server variables are the only setting which extends \/ shrinks server memory usage limits.<\/p>\n\n\n\n

Eg. max_connections, variable for specifying number of simultaneous connection, depends on OS limits to handle file handlers. No documented limit is there for the same.<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"I\u2019m having RHEL 5 (32-bit) and MySQL-5. I was trying to check how much is the Memory Utilization limits for MySQL 5 on 32bit OS. We can easily calculate the…\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[8,377,6],"tags":[59,427],"class_list":["post-321","post","type-post","status-publish","format-standard","category-mysql","category-mysql-articles","category-technical","tag-linux","tag-mysql"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t