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Overview
| Comment: | Inline the relevent parts of sqlite3ExprAlloc() into spanExpr(), for a performance improvement. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
fe89225eab777c2c9cb1cbc31092b9e3 |
| User & Date: | drh 2016-09-26 12:38:22.166 |
Context
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2016-09-26
| ||
| 14:39 | When flattening a query of the form "SELECT * FROM (SELECT * FROM tbl WHERE x=?) WHERE y=?", ensure that the final WHERE clause is "x=? AND y=?" instead of "y=? AND x=?". Although it is still not guaranteed, this makes the order in which WHERE clause terms are processed comport more closely to users expectations. (check-in: cf7f9e6d5a user: dan tags: trunk) | |
| 12:38 | Inline the relevent parts of sqlite3ExprAlloc() into spanExpr(), for a performance improvement. (check-in: fe89225eab user: drh tags: trunk) | |
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2016-09-24
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| 17:42 | Omit the LikeOp object from the parser. Change more sqlite3PExpr() calls into sqlite3ExprAlloc() calls. (check-in: 795454a3fa user: drh tags: trunk) | |
Changes
Changes to src/parse.y.
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if( Y.n>0 ) sqlite3ExprListSetName(pParse, A, &Y, 1);
sqlite3ExprListSetSpan(pParse,A,&X);
}
selcollist(A) ::= sclp(A) STAR. {
Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
A = sqlite3ExprListAppend(pParse, A, p);
}
| | | | 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 |
if( Y.n>0 ) sqlite3ExprListSetName(pParse, A, &Y, 1);
sqlite3ExprListSetSpan(pParse,A,&X);
}
selcollist(A) ::= sclp(A) STAR. {
Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
A = sqlite3ExprListAppend(pParse, A, p);
}
selcollist(A) ::= sclp(A) nm(X) DOT STAR. {
Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0, 0);
Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, &X);
Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
A = sqlite3ExprListAppend(pParse,A, pDot);
}
// An option "AS <id>" phrase that can follow one of the expressions that
// define the result set, or one of the tables in the FROM clause.
|
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}
/* Construct a new Expr object from a single identifier. Use the
** new Expr to populate pOut. Set the span of pOut to be the identifier
** that created the expression.
*/
static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token t){
| > > > > > > > > > > > > > > > > > | < | 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 |
}
/* Construct a new Expr object from a single identifier. Use the
** new Expr to populate pOut. Set the span of pOut to be the identifier
** that created the expression.
*/
static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token t){
Expr *p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)+t.n+1);
if( p ){
memset(p, 0, sizeof(Expr));
p->op = (u8)op;
p->flags = EP_Leaf;
p->iAgg = -1;
p->u.zToken = (char*)&p[1];
memcpy(p->u.zToken, t.z, t.n);
p->u.zToken[t.n] = 0;
if( sqlite3Isquote(p->u.zToken[0]) ){
if( p->u.zToken[0]=='"' ) p->flags |= EP_DblQuoted;
sqlite3Dequote(p->u.zToken);
}
#if SQLITE_MAX_EXPR_DEPTH>0
p->nHeight = 1;
#endif
}
pOut->pExpr = p;
pOut->zStart = t.z;
pOut->zEnd = &t.z[t.n];
}
}
expr(A) ::= term(A).
expr(A) ::= LP(B) expr(X) RP(E).
{spanSet(&A,&B,&E); /*A-overwrites-B*/ A.pExpr = X.pExpr;}
term(A) ::= NULL(X). {spanExpr(&A,pParse,@X,X);/*A-overwrites-X*/}
|
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860 861 862 863 864 865 866 | Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &X, 1); Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &Y, 1); Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &Z, 1); Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0); spanSet(&A,&X,&Z); /*A-overwrites-X*/ A.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0); } | | | > > > > > > | | 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 |
Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &X, 1);
Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &Y, 1);
Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &Z, 1);
Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0);
spanSet(&A,&X,&Z); /*A-overwrites-X*/
A.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
}
term(A) ::= FLOAT|BLOB(X). {spanExpr(&A,pParse,@X,X);/*A-overwrites-X*/}
term(A) ::= STRING(X). {spanExpr(&A,pParse,@X,X);/*A-overwrites-X*/}
term(A) ::= INTEGER(X). {
A.pExpr = sqlite3ExprAlloc(pParse->db, TK_INTEGER, &X, 1);
A.zStart = X.z;
A.zEnd = X.z + X.n;
if( A.pExpr ) A.pExpr->flags |= EP_Leaf;
}
expr(A) ::= VARIABLE(X). {
if( !(X.z[0]=='#' && sqlite3Isdigit(X.z[1])) ){
spanExpr(&A, pParse, TK_VARIABLE, X);
sqlite3ExprAssignVarNumber(pParse, A.pExpr);
}else{
/* When doing a nested parse, one can include terms in an expression
** that look like this: #1 #2 ... These terms refer to registers
** in the virtual machine. #N is the N-th register. */
Token t = X; /*A-overwrites-X*/
assert( t.n>=2 );
spanSet(&A, &t, &t);
if( pParse->nested==0 ){
sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);
A.pExpr = 0;
}else{
A.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, 0);
if( A.pExpr ) sqlite3GetInt32(&t.z[1], &A.pExpr->iTable);
}
}
}
expr(A) ::= expr(A) COLLATE ids(C). {
A.pExpr = sqlite3ExprAddCollateToken(pParse, A.pExpr, &C, 1);
A.zEnd = &C.z[C.n];
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