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| author | monty@mysql.com <> | 2004-03-25 15:05:01 +0200 |
|---|---|---|
| committer | monty@mysql.com <> | 2004-03-25 15:05:01 +0200 |
| commit | ebc3b3afac575b2c2a3e89823dfba217436a85c4 (patch) | |
| tree | 27e5290a14e7d3e6c7aaced5b2ce86546de4721e /heap | |
| parent | 042af556d57f305734e64c7aa047e4709288f5bd (diff) | |
| download | mariadb-git-ebc3b3afac575b2c2a3e89823dfba217436a85c4.tar.gz | |
BTREE-indexes in HEAP tables can now be used to optimize ORDER BY
Don't read character set files if we are using only the default charset. In most cases the user will not anymore get a warning about missing character set files
Compare strings with space extend instead of space strip. Now the following comparisons holds: "a" == "a " and "a\t" < "a". (Bug #3152).
Note: Because of the above fix, one has to do a REPAIR on any table that has an ascii character < 32 last in a CHAR/VARCHAR/TEXT columns.
Diffstat (limited to 'heap')
| -rw-r--r-- | heap/hp_hash.c | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/heap/hp_hash.c b/heap/hp_hash.c index d30cbc9b82f..d040f37aea0 100644 --- a/heap/hp_hash.c +++ b/heap/hp_hash.c @@ -20,6 +20,38 @@ #include <m_ctype.h> #include <assert.h> + + +/* + Find out how many rows there is in the given range + + SYNOPSIS + hp_rb_records_in_range() + info HEAP handler + inx Index to use + start_key Start of range. Null pointer if from first key + start_key_len Length of start key + start_search_flag Flag if start key should be included or not + end_key End of range. Null pointer if to last key + end_key_len Length of end key + end_search_flag Flag if start key should be included or not + + NOTES + start_search_flag can have one of the following values: + HA_READ_KEY_EXACT Include the key in the range + HA_READ_AFTER_KEY Don't include key in range + + end_search_flag can have one of the following values: + HA_READ_BEFORE_KEY Don't include key in range + HA_READ_AFTER_KEY Include all 'end_key' values in the range + + RETURN + HA_POS_ERROR Something is wrong with the index tree. + 0 There is no matching keys in the given range + number > 0 There is approximately 'number' matching rows in + the range. +*/ + ha_rows hp_rb_records_in_range(HP_INFO *info, int inx, const byte *start_key, uint start_key_len, enum ha_rkey_function start_search_flag, @@ -30,6 +62,7 @@ ha_rows hp_rb_records_in_range(HP_INFO *info, int inx, const byte *start_key, HP_KEYDEF *keyinfo= info->s->keydef + inx; TREE *rb_tree = &keyinfo->rb_tree; heap_rb_param custom_arg; + DBUG_ENTER("hp_rb_records_in_range"); info->lastinx= inx; custom_arg.keyseg= keyinfo->seg; @@ -59,10 +92,12 @@ ha_rows hp_rb_records_in_range(HP_INFO *info, int inx, const byte *start_key, end_pos= rb_tree->elements_in_tree + (ha_rows)1; } + DBUG_PRINT("info",("start_pos: %lu end_pos: %lu", (ulong) start_pos, + (ulong) end_pos)); if (start_pos == HA_POS_ERROR || end_pos == HA_POS_ERROR) - return HA_POS_ERROR; - return end_pos < start_pos ? (ha_rows) 0 : - (end_pos == start_pos ? (ha_rows) 1 : end_pos - start_pos); + DBUG_RETURN(HA_POS_ERROR); + DBUG_RETURN(end_pos < start_pos ? (ha_rows) 0 : + (end_pos == start_pos ? (ha_rows) 1 : end_pos - start_pos)); } /* Search after a record based on a key */ |