database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-01 03:47:19 +03:00
Code Activity

WL#2985 "Partition Pruning": post-review fixes: Better comments

Browse Source 
mysql-test/r/partition_pruning.result:
  WL#2985 "Partition Pruning": more tests
mysql-test/t/partition_pruning.test:
  WL#2985 "Partition Pruning": more tests
sql/handler.h:
  WL#2985 "Partition Pruning": post-review fixes: comments
This commit is contained in:
unknown
2005-12-29 09:32:46 +03:00
parent e6bff9a606
commit 78d1abbaf9
4 changed files with 48 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
sql/opt_range.cc
View File

@ -2246,11 +2246,11 @@ typedef struct st_part_prune_param
/***************************************************************
Following fields are used to store an 'iterator' that can be
used to obtain a set of used artitions.
used to obtain a set of used partitions.
**************************************************************/
/*
Start and end+1 partition "numbers". They can have two meanings depending
depending of the value of part_num_to_part_id:
of the value of part_num_to_part_id:
part_num_to_part_id_range - numbers are partition ids
part_num_to_part_id_list - numbers are indexes in part_info->list_array
*/
@ -2536,7 +2536,7 @@ static uint32 part_num_to_part_id_list(PART_PRUNE_PARAM* ppar, uint32 num)
List<SEL_IMERGE> represents "imerge1 AND imerge2 AND ...".
The set of used partitions is an intersection of used partitions sets
for imerge_{i}.
We accumulate this intersection a separate bitmap.
We accumulate this intersection in a separate bitmap.
RETURN
See find_used_partitions()
@ -2554,7 +2554,7 @@ static int find_used_partitions_imerge_list(PART_PRUNE_PARAM *ppar,
bitmap_bytes)))
{
/*
Fallback, process just first SEL_IMERGE. This can leave us with more
Fallback, process just the first SEL_IMERGE. This can leave us with more
partitions marked as used then actually needed.
*/
return find_used_partitions_imerge(ppar, merges.head());
@ -2623,20 +2623,20 @@ int find_used_partitions_imerge(PART_PRUNE_PARAM *ppar, SEL_IMERGE *imerge)
/*
Recursively walk the SEL_ARG tree, find/mark partitions that need to be used
Collect partitioning ranges for the SEL_ARG tree and mark partitions as used
SYNOPSIS
find_used_partitions()
ppar Partition pruning context.
key_tree Intervals tree to perform pruning for.
key_tree SEL_ARG range tree to perform pruning for
DESCRIPTION
This function
* recursively walks the SEL_ARG* tree collecting partitioning
"intervals";
* finds the partitions one needs to use to get rows in these intervals;
* marks these partitions as used.
* recursively walks the SEL_ARG* tree collecting partitioning "intervals"
* finds the partitions one needs to use to get rows in these intervals
* marks these partitions as used
NOTES
WHAT IS CONSIDERED TO BE "INTERVALS"
A partition pruning "interval" is equivalent to condition in one of the
forms:
@ -2687,7 +2687,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree)
{
/*
Partitioning is done by RANGE|INTERVAL(monotonic_expr(fieldX)), and
we got "const1 < fieldX < const2" interval.
we got "const1 CMP fieldX CMP const2" interval
*/
DBUG_EXECUTE("info", dbug_print_segment_range(key_tree,
ppar->range_param.
@ -2761,7 +2761,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree)
DBUG_EXECUTE("info", dbug_print_singlepoint_range(ppar->arg_stack,
ppar->part_fields););
uint32 part_id;
/* then find in which partition the {const1, ...,constN} tuple goes */
/* Find in which partition the {const1, ...,constN} tuple goes */
if (ppar->get_top_partition_id_func(ppar->part_info, &part_id))
{
res= 0; /* No satisfying partitions */
@ -2843,7 +2843,10 @@ process_next_key_part:
if (set_full_part_if_bad_ret)
{
/* Restore the "used partition iterator" to its default */
/*
Restore the "used partitions iterator" to the default setting that
specifies iteration over all partitions.
*/
ppar->part_num_to_part_id= part_num_to_part_id_range;
ppar->start_part_num= 0;
ppar->end_part_num= ppar->part_info->no_parts;