Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Clarify the purpose of the nField argument passed to sqlite3VdbeSorterInit(). |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | threads |
| Files: | files | file ages | folders |
| SHA1: |
c0c8cff17b7311bbc4fd081313a5552f |
| User & Date: | dan 2014-04-16 19:04:23.830 |
Context
|
2014-04-17
| ||
| 08:57 | Fix build problems in vdbesort.c. Add further comments and changes to make things easier to understand. (check-in: 12b190db1d user: dan tags: threads) | |
|
2014-04-16
| ||
| 19:04 | Clarify the purpose of the nField argument passed to sqlite3VdbeSorterInit(). (check-in: c0c8cff17b user: dan tags: threads) | |
| 17:41 | Change the name of vdbeIncrInit2 to vdbePmaReaderIncrInit. Add a header comment to the same function. (check-in: 6622d87675 user: dan tags: threads) | |
Changes
Changes to src/vdbesort.c.
| ︙ | ︙ | |||
790 791 792 793 794 795 796 797 798 799 800 801 802 803 |
pMerger->aTree[iOut] = iRes;
return SQLITE_OK;
}
/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
int sqlite3VdbeSorterInit(
sqlite3 *db, /* Database connection (for malloc()) */
int nField, /* Number of key fields in each record */
VdbeCursor *pCsr /* Cursor that holds the new sorter */
){
int pgsz; /* Page size of main database */
| > > > > > > > > > > > > > > > > | 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 |
pMerger->aTree[iOut] = iRes;
return SQLITE_OK;
}
/*
** Initialize the temporary index cursor just opened as a sorter cursor.
**
** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nField)
** to determine the number of fields that should be compared from the
** records being sorted. However, if the value passed as argument nField
** is non-zero and the sorter is able to guarantee a stable sort, nField
** is used instead. This is used when sorting records for a CREATE INDEX
** statement. In this case, keys are always delivered to the sorter in
** order of the primary key, which happens to be make up the final part
** of the records being sorted. So if the sort is stable, there is never
** any reason to compare PK fields and they can be ignored for a small
** performance boost.
**
** The sorter can guarantee a stable sort when running in single-threaded
** mode, but not in multi-threaded mode.
**
** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
*/
int sqlite3VdbeSorterInit(
sqlite3 *db, /* Database connection (for malloc()) */
int nField, /* Number of key fields in each record */
VdbeCursor *pCsr /* Cursor that holds the new sorter */
){
int pgsz; /* Page size of main database */
|
| ︙ | ︙ |