CBO Defaults

This information was posted on oracle-l at some point and was relevant to a version of Oracle at some point.

001 =========================================================
002
003 /* defaults */
004
005 /* Default selectivities are set low to
006
007 1. keep cost values low for future resource limiter use
008
009 2. keep cost values low for permutation cutoff in kko
010
011 Defaults are used for bind variables, general expressions and
012
013 unanalyzed tables, except for equality where defaults are not
014
015 needed for bind variables.
016
017 */
018
019 #define KKEDSREL 0.05 /* default selectivity for < >= */
020
021 #define KKEDSEQ 0.01 /* default selectivity for = */
022
023 #define KKEDSNE 0.05 /* default selectivity for != */
024
025 #define KKEDSDF 0.05 /* default selectivity for all other ops */
026
027 #define KKEDSIRL 0.009 /* default selectivity for relation on indexed col */
028
029 #define KKEDSBRL 0.009 /* def sel for relation with bind var on index col*/
030
031 #define KKEDSIEQ 0.004 /* default selectivity for = on indexed col */
032
033 #define KKEDMBR 8 /* default multiblock read factor */
034
035 #define KKEDMBW 8 /* default multiblock write factor */
036
037 #define KKEDFNR 100.0 /* default – fixed table cardinality */
038
039 #define KKEDFRL 20 /* default – fixed table row length */
040
041 #define KKEDDNR 2000.0 /* default – remote table cardinality */
042
043 #define KKEDDRL 100 /* default – remote table avg row length */
044
045 #define KKEDDNB 100 /* default – default # of blocks */
046
047 #define KKEDDSC 13.0 /* default – default scan cost */
048
049 #define KKEDILV 1 /* default – default index levels */
050
051 #define KKEDILB 25 /* default – number of index leaf blocks */
052
053 #define KKEDLBK 1 /* default – number leaf blocks/key */
054
055 #define KKEDDBK 1 /* default – number of data blocks/key */
056
057 #define KKEDKEY 100 /* default – number of distinct keys */
058
059 #define KKEDCLF (KKEDDNB*8) /* default – clustering factor */
060
061 #define KKECRI 1.5 /* remote table access cost increase factor */
062
063 #define KKECFSC 1.0 /* fixed table scan cost */
064
065 #define KKECFNB 0 /* fixed table number of blocks */
066
067 #define KKECMXB 15 /* maximum byte length for normalization */
068
069 #define KKECBBS 256.0 /* base for byte sequence normalization */
070
071 #define KKECSPC ‘ ‘ /* space byte value */
072
073 #define KKECSPD 86400.0 /* seconds per day */
074
075 #define KKESROH 10.0 /* sort per row overhead in bytes */
076
077 #define KKESAUT 0.75 /* sort area utilization */
078
079 #define KKESROP 0.10 /* sort row overhead percent */
080
081 #define KKESRML 2.0 /* sort run multiple */
082
083 #define KKESTP 0x01 /* single table predicate */
084
085 #define KKETEQ 0x02 /* equi join */
086
087 #define KKETBCPJ 0x04 /* Cartesian product join */
088
089 #define KKESOK 0x08 /* input swap ok */
090
091 #define KKESWP 0x10 /* inputs swapped */
092
093 #define KKEEQP 0x20 /* equipartitioned */
094
095 #define KKELKNWC 0x01 /* LIKE no wild card */
096
097 #define KKELKTWC 0x02 /* LIKE trailing wild card */
098
099 #define KKELKEWC 0x04 /* LIKE embedded wild card */
100
101 #define KKELKLWC 0x08 /* LIKE leading wild card */
102
103 #define KKELKOWC 0x10 /* LIKE only wild card */
104