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Added optimizer_costs.h which includes all optimizer costs

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This makes it easier to see how costs changes over commits
This commit is contained in:
Michael Widenius
2022-08-21 05:53:54 +03:00
committed by Sergei Petrunia
parent e6205c966d
commit 034aedadf2
4 changed files with 72 additions and 50 deletions
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50
sql/sql_const.h
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@@ -199,41 +199,6 @@
#define MIN_ROWS_TO_USE_TABLE_CACHE 100
#define MIN_ROWS_TO_USE_BULK_INSERT 100
/**
The following is used to decide if MySQL should use table scanning
instead of reading with keys. The number says how many evaluation of the
WHERE clause is comparable to reading one extra row from a table.
*/
#define TIME_FOR_COMPARE 5.0 // 5 WHERE compares == one read
#define TIME_FOR_COMPARE_IDX 20.0
#define IDX_BLOCK_COPY_COST ((double) 1 / TIME_FOR_COMPARE)
#define IDX_LOOKUP_COST ((double) 1 / 8)
#define MULTI_RANGE_READ_SETUP_COST (IDX_BLOCK_COPY_COST/10)
/**
Number of comparisons of table rowids equivalent to reading one row from a
table.
*/
#define TIME_FOR_COMPARE_ROWID (TIME_FOR_COMPARE*100)
/* cost1 is better that cost2 only if cost1 + COST_EPS < cost2 */
#define COST_EPS 0.001
/*
For sequential disk seeks the cost formula is:
DISK_SEEK_BASE_COST + DISK_SEEK_PROP_COST * #blocks_to_skip
The cost of average seek
DISK_SEEK_BASE_COST + DISK_SEEK_PROP_COST*BLOCKS_IN_AVG_SEEK =1.0.
*/
#define DISK_SEEK_BASE_COST ((double)0.9)
#define BLOCKS_IN_AVG_SEEK 128
#define DISK_SEEK_PROP_COST ((double)0.1/BLOCKS_IN_AVG_SEEK)
/**
Number of rows in a reference table when refereed through a not unique key.
This value is only used when we don't know anything about the key
@@ -241,21 +206,6 @@
*/
#define MATCHING_ROWS_IN_OTHER_TABLE 10
/*
Subquery materialization-related constants
*/
#define HEAP_TEMPTABLE_LOOKUP_COST 0.05
#define DISK_TEMPTABLE_LOOKUP_COST 1.0
#define SORT_INDEX_CMP_COST 0.02
#define COST_MAX (DBL_MAX * (1.0 - DBL_EPSILON))
#define COST_ADD(c,d) (COST_MAX - (d) > (c) ? (c) + (d) : COST_MAX)
#define COST_MULT(c,f) (COST_MAX / (f) > (c) ? (c) * (f) : COST_MAX)
#define MY_CHARSET_BIN_MB_MAXLEN 1
/** Don't pack string keys shorter than this (if PACK_KEYS=1 isn't used). */