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Overview
| Comment: | Must faster computation of estimated logarithm. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | nextgen-query-plan-exp |
| Files: | files | file ages | folders |
| SHA1: |
dfbca3acaeb862f24f25e7810a16ff20 |
| User & Date: | drh 2013-06-07 02:04:19.774 |
Context
|
2013-06-10
| ||
| 12:17 | Add a high-speed bypass for the NGQP for the common case of a simply query with quality constraints that outputs a single row. (check-in: 8d1ba30921 user: drh tags: nextgen-query-plan-exp) | |
|
2013-06-09
| ||
| 17:21 | High-speed version of NGQP. Still has some minor problems. (check-in: db2415fa67 user: drh tags: nextgen-query-plan-fast) | |
|
2013-06-07
| ||
| 02:04 | Must faster computation of estimated logarithm. (check-in: dfbca3acae user: drh tags: nextgen-query-plan-exp) | |
| 00:29 | Further prepare-time performance improvements. (check-in: 02741d177b user: drh tags: nextgen-query-plan-exp) | |
Changes
Changes to src/where.c.
| ︙ | ︙ | |||
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** Prepare a crude estimate of the logarithm of the input value.
** The results need not be exact. This is only used for estimating
** the total cost of performing operations with O(logN) or O(NlogN)
** complexity. Because N is just a guess, it is no great tragedy if
** logN is a little off.
*/
static WhereCost estLog(WhereCost N){
| | | | | < < | | 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 |
** Prepare a crude estimate of the logarithm of the input value.
** The results need not be exact. This is only used for estimating
** the total cost of performing operations with O(logN) or O(NlogN)
** complexity. Because N is just a guess, it is no great tragedy if
** logN is a little off.
*/
static WhereCost estLog(WhereCost N){
u32 a;
assert( sizeof(WhereCost)==4 ); /* 32-bit float input */
if( N<=0.0 ) return 0.0;
memcpy(&a, &N, 4);
return ((a >>= 23)-127)*0.3;
}
/*
** Two routines for printing the content of an sqlite3_index_info
** structure. Used for testing and debugging only. If neither
** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
** are no-ops.
|
| ︙ | ︙ | |||
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if( pDistinct && isDistinctRedundant(pParse,pTabList,&pWInfo->sWC,pDistinct) ){
pDistinct = 0;
pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
}
/* Construct the WhereLoop objects */
WHERETRACE(("*** Optimizer Start ***\n"));
rc = whereLoopAddAll(&sWLB);
if( rc ) goto whereBeginError;
/* Display all of the WhereLoop objects if wheretrace is enabled */
#ifdef WHERETRACE_ENABLED
if( sqlite3WhereTrace ){
WhereLoop *p;
| > | 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 |
if( pDistinct && isDistinctRedundant(pParse,pTabList,&pWInfo->sWC,pDistinct) ){
pDistinct = 0;
pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
}
/* Construct the WhereLoop objects */
WHERETRACE(("*** Optimizer Start ***\n"));
/* TBD: if( nTablist==1 ) whereCommonCase(&sWLB); */
rc = whereLoopAddAll(&sWLB);
if( rc ) goto whereBeginError;
/* Display all of the WhereLoop objects if wheretrace is enabled */
#ifdef WHERETRACE_ENABLED
if( sqlite3WhereTrace ){
WhereLoop *p;
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| ︙ | ︙ |