SQLite

Check-in [c9724e761b]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Performance optimization to the new affinity handling logic.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | pending
Files: files | file ages | folders
SHA3-256: c9724e761bce7a4ae63ce3c1408795915865e8d3024dcb90690456f724f0df53
User & Date: drh 2019-08-06 15:18:15.358
Context
2019-08-06
15:32
Ensure that columns of views and sub-queries that are expressions with no affinity are comparied without any type conversions, as required in the documentation. Tickets [61c853857f40da49] and [d52a29a9e6bc55c5]. (check-in: 9c8c1092a8 user: drh tags: trunk)
15:18
Performance optimization to the new affinity handling logic. (Closed-Leaf check-in: c9724e761b user: drh tags: pending)
14:37
Use 0x40 (ASCII '@') instead of 0x00 to mean "no affinity" so that columns with no affinity can appear in a zero-terminated string. Use the new SQLITE_AFF_NONE macro for this new magic number. (check-in: e8234f6939 user: drh tags: pending)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/expr.c.
︙
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253

235
236
237
238
239
240
241





242
243
244
245
246
247
248








-
-
-
-
-








    ** affinity, use that. Otherwise use no affinity.
    */
    if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
      return SQLITE_AFF_NUMERIC;
    }else{
      return SQLITE_AFF_BLOB;
    }
  }else if( aff1<=SQLITE_AFF_NONE && aff2<=SQLITE_AFF_NONE ){
    /* Neither side of the comparison is a column.  Compare the
    ** results directly.
    */
    return SQLITE_AFF_BLOB;
  }else{
    /* One side is a column, the other is not. Use the columns affinity. */
    assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE );
    return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE;
  }
}
︙
276
277
278
279
280
281
282
283
284
285
286
287





288
289
290

291
292
293
294
295
296
297

271
272
273
274
275
276
277





278
279
280
281
282


283
284
285
286
287
288
289
290
291








-
-
-
-
-
+
+
+
+
+
-
-

+








** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
  char aff = comparisonAffinity(pExpr);
  switch( aff ){
    case SQLITE_AFF_BLOB:
      return 1;
    case SQLITE_AFF_TEXT:
      return idx_affinity==SQLITE_AFF_TEXT;
  if( aff<SQLITE_AFF_TEXT ){
    return 1;
  }
  if( aff==SQLITE_AFF_TEXT ){
    return idx_affinity==SQLITE_AFF_TEXT;
    default:
      return sqlite3IsNumericAffinity(idx_affinity);
  }
  return sqlite3IsNumericAffinity(idx_affinity);
}

/*
** Return the P5 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
*/
static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
︙