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Commit1b393f4

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Avoid detoast in texteq/textne/byteaeq/byteane for unequal-length strings.
We can get the length of a compressed or out-of-line datum without actuallydetoasting it. If the lengths of two strings are unequal, we can thenconclude they are unequal without detoasting. That saves considerable workin an admittedly less-common case, without costing anything much when theoptimization doesn't apply.Noah Misch
1 parent6e1726d commit1b393f4

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1 file changed

+75
-41
lines changed

1 file changed

+75
-41
lines changed

‎src/backend/utils/adt/varlena.c‎

Lines changed: 75 additions & 41 deletions
Original file line numberDiff line numberDiff line change
@@ -1451,45 +1451,63 @@ text_cmp(text *arg1, text *arg2)
14511451
Datum
14521452
texteq(PG_FUNCTION_ARGS)
14531453
{
1454-
text*arg1=PG_GETARG_TEXT_PP(0);
1455-
text*arg2=PG_GETARG_TEXT_PP(1);
1454+
Datumarg1=PG_GETARG_DATUM(0);
1455+
Datumarg2=PG_GETARG_DATUM(1);
14561456
boolresult;
1457+
Sizelen1,
1458+
len2;
14571459

14581460
/*
14591461
* Since we only care about equality or not-equality, we can avoid all the
1460-
* expense of strcoll() here, and just do bitwise comparison.
1462+
* expense of strcoll() here, and just do bitwise comparison. In fact,
1463+
* we don't even have to do a bitwise comparison if we can show the
1464+
* lengths of the strings are unequal; which might save us from having
1465+
* to detoast one or both values.
14611466
*/
1462-
if (VARSIZE_ANY_EXHDR(arg1)!=VARSIZE_ANY_EXHDR(arg2))
1467+
len1=toast_raw_datum_size(arg1);
1468+
len2=toast_raw_datum_size(arg2);
1469+
if (len1!=len2)
14631470
result= false;
14641471
else
1465-
result= (memcmp(VARDATA_ANY(arg1),VARDATA_ANY(arg2),
1466-
VARSIZE_ANY_EXHDR(arg1))==0);
1472+
{
1473+
text*targ1=DatumGetTextPP(arg1);
1474+
text*targ2=DatumGetTextPP(arg2);
14671475

1468-
PG_FREE_IF_COPY(arg1,0);
1469-
PG_FREE_IF_COPY(arg2,1);
1476+
result= (memcmp(VARDATA_ANY(targ1),VARDATA_ANY(targ2),
1477+
len1-VARHDRSZ)==0);
1478+
1479+
PG_FREE_IF_COPY(targ1,0);
1480+
PG_FREE_IF_COPY(targ2,1);
1481+
}
14701482

14711483
PG_RETURN_BOOL(result);
14721484
}
14731485

14741486
Datum
14751487
textne(PG_FUNCTION_ARGS)
14761488
{
1477-
text*arg1=PG_GETARG_TEXT_PP(0);
1478-
text*arg2=PG_GETARG_TEXT_PP(1);
1489+
Datumarg1=PG_GETARG_DATUM(0);
1490+
Datumarg2=PG_GETARG_DATUM(1);
14791491
boolresult;
1492+
Sizelen1,
1493+
len2;
14801494

1481-
/*
1482-
* Since we only care about equality or not-equality, we can avoid all the
1483-
* expense of strcoll() here, and just do bitwise comparison.
1484-
*/
1485-
if (VARSIZE_ANY_EXHDR(arg1)!=VARSIZE_ANY_EXHDR(arg2))
1495+
/* See comment in texteq() */
1496+
len1=toast_raw_datum_size(arg1);
1497+
len2=toast_raw_datum_size(arg2);
1498+
if (len1!=len2)
14861499
result= true;
14871500
else
1488-
result= (memcmp(VARDATA_ANY(arg1),VARDATA_ANY(arg2),
1489-
VARSIZE_ANY_EXHDR(arg1))!=0);
1501+
{
1502+
text*targ1=DatumGetTextPP(arg1);
1503+
text*targ2=DatumGetTextPP(arg2);
14901504

1491-
PG_FREE_IF_COPY(arg1,0);
1492-
PG_FREE_IF_COPY(arg2,1);
1505+
result= (memcmp(VARDATA_ANY(targ1),VARDATA_ANY(targ2),
1506+
len1-VARHDRSZ)!=0);
1507+
1508+
PG_FREE_IF_COPY(targ1,0);
1509+
PG_FREE_IF_COPY(targ2,1);
1510+
}
14931511

14941512
PG_RETURN_BOOL(result);
14951513
}
@@ -2358,47 +2376,63 @@ SplitIdentifierString(char *rawstring, char separator,
23582376
Datum
23592377
byteaeq(PG_FUNCTION_ARGS)
23602378
{
2361-
bytea*arg1=PG_GETARG_BYTEA_PP(0);
2362-
bytea*arg2=PG_GETARG_BYTEA_PP(1);
2363-
intlen1,
2364-
len2;
2379+
Datumarg1=PG_GETARG_DATUM(0);
2380+
Datumarg2=PG_GETARG_DATUM(1);
23652381
boolresult;
2382+
Sizelen1,
2383+
len2;
23662384

2367-
len1=VARSIZE_ANY_EXHDR(arg1);
2368-
len2=VARSIZE_ANY_EXHDR(arg2);
2369-
2370-
/* fast path for different-length inputs */
2385+
/*
2386+
* We can use a fast path for unequal lengths, which might save us from
2387+
* having to detoast one or both values.
2388+
*/
2389+
len1=toast_raw_datum_size(arg1);
2390+
len2=toast_raw_datum_size(arg2);
23712391
if (len1!=len2)
23722392
result= false;
23732393
else
2374-
result= (memcmp(VARDATA_ANY(arg1),VARDATA_ANY(arg2),len1)==0);
2394+
{
2395+
bytea*barg1=DatumGetByteaPP(arg1);
2396+
bytea*barg2=DatumGetByteaPP(arg2);
23752397

2376-
PG_FREE_IF_COPY(arg1,0);
2377-
PG_FREE_IF_COPY(arg2,1);
2398+
result= (memcmp(VARDATA_ANY(barg1),VARDATA_ANY(barg2),
2399+
len1-VARHDRSZ)==0);
2400+
2401+
PG_FREE_IF_COPY(barg1,0);
2402+
PG_FREE_IF_COPY(barg2,1);
2403+
}
23782404

23792405
PG_RETURN_BOOL(result);
23802406
}
23812407

23822408
Datum
23832409
byteane(PG_FUNCTION_ARGS)
23842410
{
2385-
bytea*arg1=PG_GETARG_BYTEA_PP(0);
2386-
bytea*arg2=PG_GETARG_BYTEA_PP(1);
2387-
intlen1,
2388-
len2;
2411+
Datumarg1=PG_GETARG_DATUM(0);
2412+
Datumarg2=PG_GETARG_DATUM(1);
23892413
boolresult;
2414+
Sizelen1,
2415+
len2;
23902416

2391-
len1=VARSIZE_ANY_EXHDR(arg1);
2392-
len2=VARSIZE_ANY_EXHDR(arg2);
2393-
2394-
/* fast path for different-length inputs */
2417+
/*
2418+
* We can use a fast path for unequal lengths, which might save us from
2419+
* having to detoast one or both values.
2420+
*/
2421+
len1=toast_raw_datum_size(arg1);
2422+
len2=toast_raw_datum_size(arg2);
23952423
if (len1!=len2)
23962424
result= true;
23972425
else
2398-
result= (memcmp(VARDATA_ANY(arg1),VARDATA_ANY(arg2),len1)!=0);
2426+
{
2427+
bytea*barg1=DatumGetByteaPP(arg1);
2428+
bytea*barg2=DatumGetByteaPP(arg2);
23992429

2400-
PG_FREE_IF_COPY(arg1,0);
2401-
PG_FREE_IF_COPY(arg2,1);
2430+
result= (memcmp(VARDATA_ANY(barg1),VARDATA_ANY(barg2),
2431+
len1-VARHDRSZ)!=0);
2432+
2433+
PG_FREE_IF_COPY(barg1,0);
2434+
PG_FREE_IF_COPY(barg2,1);
2435+
}
24022436

24032437
PG_RETURN_BOOL(result);
24042438
}

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