mirror of
https://github.com/MariaDB/server.git
synced 2025-01-16 12:02:42 +01:00
30edd5549d
The MariaDB implementation of page_compressed tables for InnoDB used sparse files. In the worst case, in the data file, every data page will consist of some data followed by a hole. This may be extremely inefficient in some file systems. If the underlying storage device is thinly provisioned (can compress data on the fly), it would be good to write regular files (with sequences of NUL bytes at the end of each page_compressed block) and let the storage device take care of compressing the data. For reads, sparse file regions and regions containing NUL bytes will be indistinguishable. my_test_if_disable_punch_hole(): A new predicate for detecting thinly provisioned storage. (Not implemented yet.) innodb_atomic_writes: Correct the comment. buf_flush_page(): Support all values of fil_node_t::punch_hole. On a thinly provisioned storage device, we will always write NUL-padded innodb_page_size bytes also for page_compressed tables. buf_flush_freed_pages(): Remove a redundant condition. fil_space_t::atomic_write_supported: Remove. (This was duplicating fil_node_t::atomic_write.) fil_space_t::punch_hole: Remove. (Duplicated fil_node_t::punch_hole.) fil_node_t: Remove magic_n, and consolidate flags into bitfields. For punch_hole we introduce a third value that indicates a thinly provisioned storage device. fil_node_t::find_metadata(): Detect all attributes of the file. |
||
|---|---|---|
| .. | ||
| inc | ||
| r | ||
| t | ||
| disabled.def | ||