innodb_buffer_stats_by_schema and x$innodb_buffer_stats_by_schema Sys Schema Views
MariaDB starting with 10.6
These Sys Schema views were introduced in MariaDB 10.6.
Querying these views can have a noticeable performance impact on a production server.
Description
The innodb_buffer_stats_by_schema and x$innodb_buffer_stats_by_schema views 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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