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Merge recent enhancements and bug fixes from trunk.

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FossilOrigin-Name: 78bc42e664e9fa9ee21ad9762c369f291fcdf5db
This commit is contained in:
drh
2015-11-07 01:33:30 +00:00
parent e2ef7dc05b d6b7946c32
commit 98a0e0083f
36 changed files with 856 additions and 287 deletions
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39
src/sqliteInt.h
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@@ -1820,9 +1820,8 @@ struct KeyInfo {
};
/*
** An instance of the following structure holds information about a
** single index record that has already been parsed out into individual
** values.
** This object holds a record which has been parsed out into individual
** fields, for the purposes of doing a comparison.
**
** A record is an object that contains one or more fields of data.
** Records are used to store the content of a table row and to store
@@ -1830,20 +1829,40 @@ struct KeyInfo {
** the OP_MakeRecord opcode of the VDBE and is disassembled by the
** OP_Column opcode.
**
** This structure holds a record that has already been disassembled
** into its constituent fields.
** An instance of this object serves as a "key" for doing a search on
** an index b+tree. The goal of the search is to find the entry that
** is closed to the key described by this object. This object might hold
** just a prefix of the key. The number of fields is given by
** pKeyInfo->nField.
**
** The r1 and r2 member variables are only used by the optimized comparison
** functions vdbeRecordCompareInt() and vdbeRecordCompareString().
** The r1 and r2 fields are the values to return if this key is less than
** or greater than a key in the btree, respectively. These are normally
** -1 and +1 respectively, but might be inverted to +1 and -1 if the b-tree
** is in DESC order.
**
** The key comparison functions actually return default_rc when they find
** an equals comparison. default_rc can be -1, 0, or +1. If there are
** multiple entries in the b-tree with the same key (when only looking
** at the first pKeyInfo->nFields,) then default_rc can be set to -1 to
** cause the search to find the last match, or +1 to cause the search to
** find the first match.
**
** The key comparison functions will set eqSeen to true if they ever
** get and equal results when comparing this structure to a b-tree record.
** When default_rc!=0, the search might end up on the record immediately
** before the first match or immediately after the last match. The
** eqSeen field will indicate whether or not an exact match exists in the
** b-tree.
*/
struct UnpackedRecord {
KeyInfo *pKeyInfo; /* Collation and sort-order information */
Mem *aMem; /* Values */
u16 nField; /* Number of entries in apMem[] */
i8 default_rc; /* Comparison result if keys are equal */
u8 errCode; /* Error detected by xRecordCompare (CORRUPT or NOMEM) */
Mem *aMem; /* Values */
int r1; /* Value to return if (lhs > rhs) */
int r2; /* Value to return if (rhs < lhs) */
i8 r1; /* Value to return if (lhs > rhs) */
i8 r2; /* Value to return if (rhs < lhs) */
u8 eqSeen; /* True if an equality comparison has been seen */
};