commit 012086a88c5f206b02747899e5cb86ce41459e53 Author: jcoleman Date: Wed Nov 14 16:49:52 2018 +0000 Prove IS NOT NULL inference for large arrays For the purposes of predicate proof testing we limit ScalarArrayOpExpr decomposition to arrays with <= MAX_SAOP_ARRAY_SIZE items (currently 100 items). However all scalar array ops IS NOT NULL can be inferred trivially without decomposing into AND/OR chains. We teach predtest to check for strict operators in ScalarArrayOpExpr nodes instead of relying on checking strictness of operators in AND/OR chains. This allows the planner to use partial indexes of the form "WHERE foo IS NOT NULL" when the query's WHERE clause involves a scalar array op like "foo IN (1,2,...101)". diff --git a/src/backend/optimizer/util/predtest.c b/src/backend/optimizer/util/predtest.c index 3d5ef6922c..4968136d79 100644 --- a/src/backend/optimizer/util/predtest.c +++ b/src/backend/optimizer/util/predtest.c @@ -815,7 +815,7 @@ predicate_refuted_by_recurse(Node *clause, Node *predicate, * This function also implements enforcement of MAX_SAOP_ARRAY_SIZE: if a * ScalarArrayOpExpr's array has too many elements, we just classify it as an * atom. (This will result in its being passed as-is to the simple_clause - * functions, which will fail to prove anything about it.) Note that we + * functions, many of which will fail to prove anything about it.) Note that we * cannot just stop after considering MAX_SAOP_ARRAY_SIZE elements; in general * that would result in wrong proofs, rather than failing to prove anything. */ @@ -1351,6 +1351,42 @@ clause_is_strict_for(Node *clause, Node *subexpr) return false; } + /* + * Since we limit decomposing ScalarArrayOpExpr nodes into AND/OR quals + * to arrays with at most MAX_SAOP_ARRAY_SIZE items, we need to handle + * scalar array ops separately (this case will occur when the array has + * more than MAX_SAOP_ARRAY_SIZE items). + */ + if (IsA(clause, ScalarArrayOpExpr)) + { + ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause; + if (op_strict(saop->opno) && + clause_is_strict_for((Node *) linitial(saop->args), subexpr)) + { + Node *arraynode = (Node *) lsecond(saop->args); + int nelems = 0; + + if (arraynode && IsA(arraynode, Const) && + !((Const *) arraynode)->constisnull) + { + ArrayType *arrayval; + arrayval = DatumGetArrayTypeP(((Const *) arraynode)->constvalue); + nelems = ArrayGetNItems(ARR_NDIM(arrayval), ARR_DIMS(arrayval)); + } + else if (arraynode && IsA(arraynode, ArrayExpr) && + !((ArrayExpr *) arraynode)->multidims) + nelems = list_length(((ArrayExpr *) arraynode)->elements); + + /* + * Empty AND/OR groups resolve to true or false rather than null, + * so in addition to verifying the operation is otherwise strict, + * we also have to verify we have a non-empty array. + */ + if (nelems > 0) + return true; + } + } + return false; } diff --git a/src/test/modules/test_predtest/expected/test_predtest.out b/src/test/modules/test_predtest/expected/test_predtest.out index 5574e03204..7210845b77 100644 --- a/src/test/modules/test_predtest/expected/test_predtest.out +++ b/src/test/modules/test_predtest/expected/test_predtest.out @@ -837,3 +837,97 @@ w_i_holds | f s_r_holds | f w_r_holds | f +-- For the next few tests, We want to test an array longer than +-- MAX_SAOP_ARRAY_SIZE so that we're not relying on predtest turning +-- the array op into set of OR quals. We also need to include at least +-- one null value to demonstrate strict operators are checked properly. +select * from test_predtest($$ +select x is not null, x = any(array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null +]) +from integers +$$); +-[ RECORD 1 ]-----+-- +strong_implied_by | t +weak_implied_by | f +strong_refuted_by | f +weak_refuted_by | f +s_i_holds | t +w_i_holds | f +s_r_holds | f +w_r_holds | f + +select * from test_predtest($$ +select y is not null, x = any(array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null +]) +from integers +$$); +-[ RECORD 1 ]-----+-- +strong_implied_by | f +weak_implied_by | f +strong_refuted_by | f +weak_refuted_by | f +s_i_holds | f +w_i_holds | f +s_r_holds | f +w_r_holds | f + +select * from test_predtest($$ +with a(vals) as ( + select array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null + ] +) +select x is not null, x = any((select vals from a)::int[]) +from integers +$$); +-[ RECORD 1 ]-----+-- +strong_implied_by | t +weak_implied_by | f +strong_refuted_by | f +weak_refuted_by | f +s_i_holds | t +w_i_holds | f +s_r_holds | f +w_r_holds | f + +-- Verify ScalarArrayOpExpr empty array base cases since they resolve +-- to true or false instead of null. +select * from test_predtest($$ +select x is not null, x = any(array[]::int[]) +from integers +$$); +-[ RECORD 1 ]-----+-- +strong_implied_by | t +weak_implied_by | t +strong_refuted_by | t +weak_refuted_by | t +s_i_holds | t +w_i_holds | t +s_r_holds | t +w_r_holds | t + +select * from test_predtest($$ +select x is null, x = any(array[]::int[]) +from integers +$$); +-[ RECORD 1 ]-----+-- +strong_implied_by | t +weak_implied_by | t +strong_refuted_by | t +weak_refuted_by | t +s_i_holds | t +w_i_holds | t +s_r_holds | t +w_r_holds | t + diff --git a/src/test/modules/test_predtest/sql/test_predtest.sql b/src/test/modules/test_predtest/sql/test_predtest.sql index 2734735843..069521421c 100644 --- a/src/test/modules/test_predtest/sql/test_predtest.sql +++ b/src/test/modules/test_predtest/sql/test_predtest.sql @@ -325,3 +325,53 @@ select * from test_predtest($$ select x <= y, x = any(array[1,3,y]) from integers $$); + +-- For the next few tests, We want to test an array longer than +-- MAX_SAOP_ARRAY_SIZE so that we're not relying on predtest turning +-- the array op into set of OR quals. We also need to include at least +-- one null value to demonstrate strict operators are checked properly. +select * from test_predtest($$ +select x is not null, x = any(array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null +]) +from integers +$$); + +select * from test_predtest($$ +select y is not null, x = any(array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null +]) +from integers +$$); + +select * from test_predtest($$ +with a(vals) as ( + select array[ + 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28, + 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53, + 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78, + 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,null + ] +) +select x is not null, x = any((select vals from a)::int[]) +from integers +$$); + +-- Verify ScalarArrayOpExpr empty array base cases since they resolve +-- to true or false instead of null. +select * from test_predtest($$ +select x is not null, x = any(array[]::int[]) +from integers +$$); + +select * from test_predtest($$ +select x is null, x = any(array[]::int[]) +from integers +$$); +