Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Adjust the output row estimating logic when using STAT2. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | query-planner-tweaks |
| Files: | files | file ages | folders |
| SHA1: |
c8ba8855d8e93cd1e7dbbc9398a5f850 |
| User & Date: | drh 2011-08-03 01:07:25 |
Context
|
2011-08-05
| ||
| 01:09 | Allow the sqlite_stat2 table to contain a number of samples other than the default of 10. (check-in: b9d41c34 user: drh tags: query-planner-tweaks) | |
|
2011-08-03
| ||
| 01:07 | Adjust the output row estimating logic when using STAT2. (check-in: c8ba8855 user: drh tags: query-planner-tweaks) | |
|
2011-08-02
| ||
| 20:14 | Exclude the 8_3_names.test script from the inmemory_journal permutation. (check-in: 78fc94c8 user: drh tags: trunk) | |
Changes
Changes to src/sqliteInt.h.
77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 |
#endif /* ** The number of samples of an index that SQLite takes in order to ** construct a histogram of the table content when running ANALYZE ** and with SQLITE_ENABLE_STAT2 */ #define SQLITE_INDEX_SAMPLES 10 /* ** The following macros are used to cast pointers to integers and ** integers to pointers. The way you do this varies from one compiler ** to the next, so we have developed the following set of #if statements ** to generate appropriate macros for a wide range of compilers. ** |
> | > |
77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 |
#endif /* ** The number of samples of an index that SQLite takes in order to ** construct a histogram of the table content when running ANALYZE ** and with SQLITE_ENABLE_STAT2 */ #ifndef SQLITE_INDEX_SAMPLES # define SQLITE_INDEX_SAMPLES 10 #endif /* ** The following macros are used to cast pointers to integers and ** integers to pointers. The way you do this varies from one compiler ** to the next, so we have developed the following set of #if statements ** to generate appropriate macros for a wide range of compilers. ** |
Changes to src/where.c.
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
....
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
|
if( pRhs==0 ) return SQLITE_NOTFOUND;
rc = whereRangeRegion(pParse, p, pRhs, 0, &iLower);
if( rc ) goto whereEqualScanEst_cancel;
rc = whereRangeRegion(pParse, p, pRhs, 1, &iUpper);
if( rc ) goto whereEqualScanEst_cancel;
WHERETRACE(("equality scan regions: %d..%d\n", iLower, iUpper));
if( iLower>=iUpper ){
nRowEst = p->aiRowEst[0]/(SQLITE_INDEX_SAMPLES*2);
if( nRowEst<*pnRow ) *pnRow = nRowEst;
}else{
nRowEst = (iUpper-iLower)*p->aiRowEst[0]/SQLITE_INDEX_SAMPLES;
*pnRow = nRowEst;
}
whereEqualScanEst_cancel:
................................................................................
for(i=nSpan=0; i<=SQLITE_INDEX_SAMPLES; i++){
if( aSpan[i] ){
nSpan++;
}else if( aSingle[i] ){
nSingle++;
}
}
nRowEst = (nSpan*2+nSingle)*p->aiRowEst[0]/(2*SQLITE_INDEX_SAMPLES)
+ nNotFound*p->aiRowEst[1];
if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
*pnRow = nRowEst;
WHERETRACE(("IN row estimate: nSpan=%d, nSingle=%d, nNotFound=%d, est=%g\n",
nSpan, nSingle, nNotFound, nRowEst));
}
sqlite3ValueFree(pVal);
|
|
|
|
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
....
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
|
if( pRhs==0 ) return SQLITE_NOTFOUND;
rc = whereRangeRegion(pParse, p, pRhs, 0, &iLower);
if( rc ) goto whereEqualScanEst_cancel;
rc = whereRangeRegion(pParse, p, pRhs, 1, &iUpper);
if( rc ) goto whereEqualScanEst_cancel;
WHERETRACE(("equality scan regions: %d..%d\n", iLower, iUpper));
if( iLower>=iUpper ){
nRowEst = p->aiRowEst[0]/(SQLITE_INDEX_SAMPLES*3);
if( nRowEst<*pnRow ) *pnRow = nRowEst;
}else{
nRowEst = (iUpper-iLower)*p->aiRowEst[0]/SQLITE_INDEX_SAMPLES;
*pnRow = nRowEst;
}
whereEqualScanEst_cancel:
................................................................................
for(i=nSpan=0; i<=SQLITE_INDEX_SAMPLES; i++){
if( aSpan[i] ){
nSpan++;
}else if( aSingle[i] ){
nSingle++;
}
}
nRowEst = (nSpan*3+nSingle)*p->aiRowEst[0]/(3*SQLITE_INDEX_SAMPLES)
+ nNotFound*p->aiRowEst[1];
if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
*pnRow = nRowEst;
WHERETRACE(("IN row estimate: nSpan=%d, nSingle=%d, nNotFound=%d, est=%g\n",
nSpan, nSingle, nNotFound, nRowEst));
}
sqlite3ValueFree(pVal);
|
Changes to test/analyze5.test.
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
...
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
47 {z>=-100 AND z<=0.0} t1z 400
48 {z>=-100 AND z<0.0} t1z 50
49 {z>=-100 AND z<=1.0} t1z 700
50 {z>=-100 AND z<2.0} t1z 700
51 {z>=-100 AND z<=2.0} t1z 900
52 {z>=-100 AND z<3.0} t1z 900
101 {z=-1} t1z 50
102 {z=0} t1z 400
103 {z=1} t1z 300
104 {z=2} t1z 200
105 {z=3} t1z 100
106 {z=4} t1z 50
107 {z=-10.0} t1z 50
108 {z=0.0} t1z 400
109 {z=1.0} t1z 300
110 {z=2.0} t1z 200
111 {z=3.0} t1z 100
112 {z=4.0} t1z 50
113 {z=1.5} t1z 50
114 {z=2.5} t1z 50
201 {z IN (-1)} t1z 50
202 {z IN (0)} t1z 400
203 {z IN (1)} t1z 300
204 {z IN (2)} t1z 200
205 {z IN (3)} t1z 100
206 {z IN (4)} t1z 50
207 {z IN (0.5)} t1z 50
208 {z IN (0,1)} t1z 700
209 {z IN (0,1,2)} t1z 900
210 {z IN (0,1,2,3)} {} 100
211 {z IN (0,1,2,3,4,5)} {} 100
212 {z IN (1,2)} t1z 500
213 {z IN (2,3)} t1z 300
214 {z=3 OR z=2} t1z 300
215 {z IN (-1,3)} t1z 150
216 {z=-1 OR z=3} t1z 150
300 {y=0} {} 100
301 {y=1} t1y 50
302 {y=0.1} t1y 50
400 {x IS NULL} t1x 400
} {
# Verify that the expected index is used with the expected row count
do_test analyze5-1.${testid}a {
set x [lindex [eqp "SELECT * FROM t1 WHERE $where"] 3]
................................................................................
ANALYZE;
}
# Verify that range queries generate the correct row count estimates
#
foreach {testid where index rows} {
500 {x IS NULL AND u='charlie'} t1u 20
501 {x=1 AND u='charlie'} t1x 5
502 {x IS NULL} {} 100
503 {x=1} t1x 50
504 {x IS NOT NULL} t1x 25
505 {+x IS NOT NULL} {} 500
506 {upper(x) IS NOT NULL} {} 500
} {
# Verify that the expected index is used with the expected row count
do_test analyze5-1.${testid}a {
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
...
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
47 {z>=-100 AND z<=0.0} t1z 400
48 {z>=-100 AND z<0.0} t1z 50
49 {z>=-100 AND z<=1.0} t1z 700
50 {z>=-100 AND z<2.0} t1z 700
51 {z>=-100 AND z<=2.0} t1z 900
52 {z>=-100 AND z<3.0} t1z 900
101 {z=-1} t1z 33
102 {z=0} t1z 400
103 {z=1} t1z 300
104 {z=2} t1z 200
105 {z=3} t1z 100
106 {z=4} t1z 33
107 {z=-10.0} t1z 33
108 {z=0.0} t1z 400
109 {z=1.0} t1z 300
110 {z=2.0} t1z 200
111 {z=3.0} t1z 100
112 {z=4.0} t1z 33
113 {z=1.5} t1z 33
114 {z=2.5} t1z 33
201 {z IN (-1)} t1z 33
202 {z IN (0)} t1z 400
203 {z IN (1)} t1z 300
204 {z IN (2)} t1z 200
205 {z IN (3)} t1z 100
206 {z IN (4)} t1z 33
207 {z IN (0.5)} t1z 33
208 {z IN (0,1)} t1z 700
209 {z IN (0,1,2)} t1z 900
210 {z IN (0,1,2,3)} {} 100
211 {z IN (0,1,2,3,4,5)} {} 100
212 {z IN (1,2)} t1z 500
213 {z IN (2,3)} t1z 300
214 {z=3 OR z=2} t1z 300
215 {z IN (-1,3)} t1z 133
216 {z=-1 OR z=3} t1z 133
300 {y=0} {} 100
301 {y=1} t1y 33
302 {y=0.1} t1y 33
400 {x IS NULL} t1x 400
} {
# Verify that the expected index is used with the expected row count
do_test analyze5-1.${testid}a {
set x [lindex [eqp "SELECT * FROM t1 WHERE $where"] 3]
................................................................................
ANALYZE;
}
# Verify that range queries generate the correct row count estimates
#
foreach {testid where index rows} {
500 {x IS NULL AND u='charlie'} t1u 20
501 {x=1 AND u='charlie'} t1x 3
502 {x IS NULL} {} 100
503 {x=1} t1x 33
504 {x IS NOT NULL} t1x 25
505 {+x IS NOT NULL} {} 500
506 {upper(x) IS NOT NULL} {} 500
} {
# Verify that the expected index is used with the expected row count
do_test analyze5-1.${testid}a {
|
Changes to test/analyze7.test.
95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 |
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
}
do_test analyze7-3.3 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
do_test analyze7-3.4 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b=?) (~2 rows)}}
do_test analyze7-3.5 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND c=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
do_test analyze7-3.6 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND d=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=? AND d=?) (~1 rows)}}
finish_test
|
| > > | |
95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 |
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
}
do_test analyze7-3.3 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
do_test analyze7-3.4 {
set x [execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND b=123}]
regsub -all {[bcd]+} $x {x} x
set x
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1x (x=?) (~2 rows)}}
do_test analyze7-3.5 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND c=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
do_test analyze7-3.6 {
execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND d=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=? AND d=?) (~1 rows)}}
finish_test
|