Update of query cache code.

Changed some sql_alloc() -> thd->alloc()
Removed a lot of compiler warnings on Linux Alpha (64 bit)
Fixed some core dumps on 64 bit systems (wrong type for packet_len)


Docs/manual.texi:
  Added base information about the query cache.
include/hash.h:
  Export hash_replace
include/myisam.h:
  Update of query cache code
libmysql/net.c:
  Add casts to make things safe on 64 bit systems.
myisam/mi_write.c:
  Update of query cache code
myisammrg/myrg_extra.c:
  Update of query cache code
mysys/hash.c:
  Added safety check to hash_replace
sql/field.cc:
  Removed compiler warnings.
sql/field.h:
  Removed compiler warnings
sql/ha_myisam.cc:
  Fixed wrong type of packet_len
sql/item.h:
  Remove warnings
sql/log_event.cc:
  Cleanup
sql/log_event.h:
  Cleanup to make code more readable
sql/mf_iocache.cc:
  Fixed wrong type
sql/mysql_priv.h:
  Update of query cache code
sql/mysqld.cc:
  Update of query cache code
sql/net_serv.cc:
  Remove compiler warnings
sql/opt_range.h:
  Remove compiler warnings
sql/sql_cache.cc:
  Update of query cache code
sql/sql_cache.h:
  Update of query cache code
sql/sql_class.h:
  Cleanup
sql/sql_insert.cc:
  Use thd->alloc() instead of sql_alloc()
sql/sql_parse.cc:
  Fixed compiler warnings.
  Changed some sql_alloc() -> thd->alloc()
sql/sql_select.cc:
  Changed sql_alloc() -> thd_alloc()
sql/sql_select.h:
  Faster alloc()
sql/sql_show.cc:
  Update of query cache code
sql/sql_table.cc:
  Faster alloc()
sql/table.cc:
  Faster alloc()

Docs/manual.texi

@@ -18100,6 +18100,9 @@ differ somewhat:
 | protocol_version             | 10                        |
 | record_buffer                | 131072                    |
 | query_buffer_size            | 0                         |
+| query_cache_limit            | 1048576		   |
+| query_cache_size             | 16768060                  |
+| query_cache_startup_type     | 1                         |
 | safe_show_database           | OFF                       |
 | server_id                    | 0                         |
 | skip_locking                 | ON                        |
@@ -18497,6 +18500,18 @@ buffer to avoid a disk seeks.  If not set, then it's set to the value of
 The initial allocation of the query buffer. If most of your queries are
 long (like when inserting blobs), you should increase this!
 
+@item @code{query_cache_limit}
+Don't cache results that are bigger than this. (Default 1M).
+
+@item @code{query_cache_size}
+The memory allocated to store results from old queries.  If this is zero
+the query cache is disabled.
+
+@item @code{query_cache_startup_type}
+This may have be set to 0 (cache results but don't retrieve results from
+cache), 1 (cache results by defaults) or 2 (only cache @code{SELECT}'s marked
+with @code{SQL_CACHE}).
+
 @item @code{safe_show_databases}
 Don't show databases for which the user doesn't have any database or
 table privileges. This can improve security if you're concerned about
@@ -25730,6 +25745,17 @@ flag again, the @code{SQL_MAX_JOIN_SIZE} variable will be ignored.
 You can set a default value for this variable by starting @code{mysqld} with
 @code{-O max_join_size=#}.
 
+@item SQL_QUERY_CACHE_TYPE = [OFF | ON | DEMAND]
+@item SQL_QUERY_CACHE_TYPE = [0   | 1  | 2]
+
+The numbers are standing for the correspoding verbose option.
+
+@multitable @columnfractions .3 .7
+@item 0 or OFF @tab Cache @code{SELECT} results, but don't retrieve results from cache.
+@item 1 or ON @tab Cache all @code{SELECT}'s that are not marked with @code{SQL_NO_CACHE}.
+@item 2 or DEMAND @tab Cache only @code{SELECT SQL_CACHE}) queries.
+@end multitable
+
 @item SQL_SAFE_UPDATES = 0 | 1
 If set to @code{1}, MySQL will abort if an @code{UPDATE} or
 @code{DELETE} is attempted that doesn't use a key or @code{LIMIT} in the
@@ -31085,7 +31111,7 @@ mysql> SELECT id,FLOOR(value/100) FROM tbl_name ORDER BY RAND();
 @c help SELECT
 @example
 SELECT [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
-       [HIGH_PRIORITY]
+       [SQL_CACHE | SQL_NO_CACHE] [HIGH_PRIORITY]
        [DISTINCT | DISTINCTROW | ALL]
     select_expression,...
     [INTO @{OUTFILE | DUMPFILE@} 'file_name' export_options]
@@ -31213,9 +31239,8 @@ mysql> select user,max(salary) AS sum from users
 @end example
 
 @item
-@code{SQL_SMALL_RESULT}, @code{SQL_BIG_RESULT}, @code{SQL_BUFFER_RESULT},
-@code{STRAIGHT_JOIN}, and @code{HIGH_PRIORITY} are MySQL extensions
-to ANSI SQL92.
+All options beginning with @code{SQL_}, @code{STRAIGHT_JOIN}, and
+@code{HIGH_PRIORITY} are MySQL extensions to ANSI SQL.
 
 @item
 @code{HIGH_PRIORITY} will give the @code{SELECT} higher priority than
@@ -31243,6 +31268,14 @@ result set will be small.  In this case, MySQL will use fast
 temporary tables to store the resulting table instead of using sorting. In
 MySQL Version 3.23 this shouldn't normally be needed.
 
+@item
+@code{SQL_CACHE} tells MySQL to store the query result in the query cache
+even if you are using @code{SQL_QUERY_CACHE_METHOD} 2 (= @code{DEMAND}).
+
+@item
+@code{SQL_NO_CACHE} tells MySL to not store the query result in the
+query cache.
+
 @item
 @cindex @code{GROUP BY}, extensions to ANSI SQL
 If you use @code{GROUP BY}, the output rows will be sorted according to the
@@ -46164,6 +46197,11 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
 
 @itemize @bullet
 @item
+A new query cache to cache results from identical @code{SELECT} queries.
+@item
+Fixed core dump bug on 64 bit machines when it got a wrong communication
+packet.
+@item
 @code{MATCH ... AGAINST(... IN BOOLEAN MODE)} can now work
 without @code{FULLTEXT} index.
 @item