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Merge zgreant@work.mysql.com:/home/bk/mysql-4.0

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into mysql.com:/home/zak/Work/bk/mysql-4.0


Docs/manual.texi:
  Auto merged
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unknown 2002-07-09 22:15:58 -06:00
commit b5d63780ff
2 changed files with 19 additions and 15 deletions
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1
BitKeeper/etc/logging_ok
View file

@ -69,3 +69,4 @@ zak@balfor.local
zak@linux.local
salle@geopard.(none)
walrus@mysql.com
zgreant@mysql.com

33
Docs/manual.texi
View file

@ -30674,12 +30674,12 @@ mysql> SELECT INTERVAL(22, 23, 30, 44, 200);
@end example
@end table
If you are comparing case-sensitive string with any of the standard
operators (@code{=}, @code{<>}..., but not @code{LIKE}) end space will
be ignored.
If you are comparing case-insensitive strings with any of the standard
operators (@code{=}, @code{<>}..., but not @code{LIKE}) trailing whitespace
(spaces, tabs and newlines) will be ignored.
@example
mysql> SELECT "a" ="A ";
mysql> SELECT "a" ="A \n";
-> 1
@end example
@ -36874,28 +36874,26 @@ parameters to @code{FULLTEXT} in @code{CREATE/ALTER TABLE}).
From version 4.0.1, @code{MySQL server} features a @code{Query Cache}.
When in use, the query cache stores the text of a @code{SELECT} query
together with the corresponding result that is sent to a client.
If another identical query is received, the server can then retrieve
together with the corresponding result that was sent to the client.
If an identical query is later received, the server will retrieve
the results from the query cache rather than parsing and executing the
same query again.
@strong{NOTE:} The query cache does not return stale data. When data
is modified, any relevant entries in the query cache are flushed.
The query cache is extremely useful in an environment where (some)
tables don't change very often and you have a lot of identical queries.
This is a typical situation for many web servers that use a lot of
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):
Below is some performance data for the query cache. (These results were
generated by running the MySQL benchmark suite on a Linux Alpha
2 x 500 MHz with 2GB RAM and a 64MB query cache):
@itemize @bullet
@item
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.
(query cache can be excluded from code with help of configure option
@code{--without-query-cache})
@item
If all of the queries you're preforming are simple (such as selecting a
If all of the queries you're performing are simple (such as selecting a
row from a table with one row); but still differ so that the queries can
not be cached, the overhead for having the query cache active is 13%.
This could be regarded as the worst case scenario. However, in real life,
@ -36905,6 +36903,11 @@ is normally significantly lower.
Searches after one row in a one row table is 238% faster.
This can be regarded as close to the minimum speedup to be expected for
a query that is cached.
@item
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.
(query cache can be excluded from code with help of configure option
@code{--without-query-cache})
@end itemize
@menu