Skip to content
Projects
Groups
Snippets
Help
Loading...
Help
Support
Keyboard shortcuts
?
Submit feedback
Contribute to GitLab
Sign in / Register
Toggle navigation
M
MariaDB
Project overview
Project overview
Details
Activity
Releases
Repository
Repository
Files
Commits
Branches
Tags
Contributors
Graph
Compare
Issues
0
Issues
0
List
Boards
Labels
Milestones
Merge Requests
0
Merge Requests
0
CI / CD
CI / CD
Pipelines
Jobs
Schedules
Analytics
Analytics
CI / CD
Repository
Value Stream
Wiki
Wiki
Snippets
Snippets
Members
Members
Collapse sidebar
Close sidebar
Activity
Graph
Create a new issue
Jobs
Commits
Issue Boards
Open sidebar
nexedi
MariaDB
Commits
eada6ed9
Commit
eada6ed9
authored
Dec 20, 2001
by
unknown
Browse files
Options
Browse Files
Download
Email Patches
Plain Diff
Some Query Cache fixups.
Added info about two new Query Cache status variables.
parent
7a8ce131
Changes
1
Show whitespace changes
Inline
Side-by-side
Showing
1 changed file
with
18 additions
and
6 deletions
+18
-6
Docs/manual.texi
Docs/manual.texi
+18
-6
No files found.
Docs/manual.texi
View file @
eada6ed9
...
...
@@ -35523,11 +35523,11 @@ dynamic content.
Following are some performance data for the query cache
(We got these by running the MySQL benchmark suite on a Linux Alpha
2x500 MHz with 2GB RAM and a 64MB query cache)
.
2x500 MHz with 2GB RAM and a 64MB query cache)
:
@itemize @bullet
@item
If want to disable the query cache code set @code{query_cache_size=0}.
If
you
want to disable the query cache code set @code{query_cache_size=0}.
By disabling the query cache code there is no noticeable overhead.
@item
If all of the queries you're preforming are simple (such as selecting a
...
...
@@ -35578,7 +35578,7 @@ found rows is also stored in the cache.
If a table changes (@code{INSERT}, @code{UPDATE}, @code{DELETE},
@code{TRUNCATE}, @code{ALTER} or @code{DROP TABLE|DATABASE}),
then all cached queries that used this table (possibly through a
MRG_MyISAM
table!) become invalid and are removed from the cache.
@code{MRG_MyISAM}
table!) become invalid and are removed from the cache.
Currently all @code{InnoDB} tables are invalidated on @code{COMMIT},
in the future this will be changed so only tables changed in the
...
...
@@ -35695,18 +35695,30 @@ You can monitor query cache performance in @code{SHOW STATUS}:
@item @code{Qcache_inserts}
@tab Number of queries added to the cache.
@item @code{Qcache_hits}
@tab Number of cache hits
@tab Number of cache hits
.
@item @code{Qcache_not_cached}
@tab Number of non-cached queries
(not cachable, or due to
SQL_QUERY_CACHE_TYPE)
(not cachable, or due to
@code{SQL_QUERY_CACHE_TYPE}).
@item @code{Qcache_free_memory}
@tab Amount of free memory for query cache.
@item @code{Qcache_total_blocks}
@tab Total number of blocks in query cache.
@item @code{Qcache_free_blocks}
@tab Number of free memory blocks in query cache.
@end multitable
Please note:
Total number of queries =
@code{Qcache_inserts} + @code{Qcache_hits} + @code{Qcache_not_cached}.
The query cache uses variable length blocks, so @code{Qcache_total_blocks}
and @code{Qcache_free_blocks} may indicate query cache memory fragmentation.
After @code{FLUSH QUERY CACHE} only a single (big) free block remains.
Note: Every query needs a minimum of two blocks (one for the query text
and one or more for the query results). Also, every table that is used
by a query needs one block, but if two or more queries use same table
only one block needs to be allocated.
@node Table types, Clients, Reference, Top
@chapter MySQL Table Types
Write
Preview
Markdown
is supported
0%
Try again
or
attach a new file
Attach a file
Cancel
You are about to add
0
people
to the discussion. Proceed with caution.
Finish editing this message first!
Cancel
Please
register
or
sign in
to comment