innodb_buffer_stats_by_schema and x$innodb_buffer_stats_by_schema Sys Schema Views
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MariaDB starting with 10.6
These Sys Schema views were introduced in MariaDB 10.6.
Querying these views can have a noticeable performance impact on a production server.
Description
The innodb_buffer_stats_by_schema
and x$innodb_buffer_stats_by_schema
views views summarize information from the Information Schema INNODB_BUFFER_PAGE table, grouped by schema. Rows are sorted by descending buffer size by default.
The innodb_buffer_stats_by_schema
view is intended to be easier for human reading, while the x$innodb_buffer_stats_by_schema
view provides the data in raw form, intended for tools that process the data.
They contain the following columns:
Column | Description |
---|---|
object_schema | Object schema name, or InnoDB System if the table belongs to the InnoDB storage engine. |
allocated | Total number of bytes allocated for the schema. |
data | Total number of data bytes allocated for the schema. |
pages | Total number of pages allocated for the schema. |
pages_hashed | Total number of hashed pages allocated for the schema. |
pages_old | Total number of old pages allocated for the schema. |
rows_cached | Total number of cached rows for the schema. |
Example
SELECT * FROM sys.innodb_buffer_stats_by_schema\G *************************** 1. row *************************** object_schema: InnoDB System allocated: 160.00 KiB data: 6.21 KiB pages: 10 pages_hashed: 10 pages_old: 10 rows_cached: 21 *************************** 2. row *************************** object_schema: mysql allocated: 112.00 KiB data: 1.73 KiB pages: 7 pages_hashed: 7 pages_old: 7 rows_cached: 5 *************************** 3. row *************************** object_schema: test allocated: 64.00 KiB data: 0 bytes pages: 4 pages_hashed: 4 pages_old: 4 rows_cached: 0 SELECT * FROM sys.x$innodb_buffer_stats_by_schema\G *************************** 1. row *************************** object_schema: InnoDB System allocated: 163840 data: 6362 pages: 10 pages_hashed: 0 pages_old: 0 rows_cached: 21 *************************** 2. row *************************** object_schema: mysql allocated: 114688 data: 1775 pages: 7 pages_hashed: 0 pages_old: 0 rows_cached: 5 *************************** 3. row *************************** object_schema: test allocated: 65536 data: 0 pages: 4 pages_hashed: 0 pages_old: 0 rows_cached: 0
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