predicatepushdown.out

derby database source code.good for you.

null				qualifiers:
None
ij> -- Next set of queries tests pushdown of predicates whose
-- column references do not reference base tables--ex. they
-- reference literals, aggregates, or subqueries.  We don't
-- check the query plans here, we're just checking to make
-- sure pushdown doesn't cause problems during compilation/
-- execution.  In the case of regressions, errors that might
-- show up here include compile-time NPEs, execution-time
-- NPEs, errors saying no predicate was found for a hash join,
-- and/or type comparison errors caused by incorrect column
-- numbers for scoped predicates.
create table tc (c1 char, c2 char, c3 char, c int);
0 rows inserted/updated/deleted
ij> create view vz (z1, z2, z3, z4) as
  select distinct xx1.c1, xx1.c2, 'bokibob' bb, xx1.c from
    (select c1, c, c2, c3 from tc) xx1
      union select 'i','j','j',i from t2;
0 rows inserted/updated/deleted
ij> create view vz2 (z1, z2, z3, z4) as
  select distinct xx1.c1, xx1.c2, 'bokibob' bb, xx1.c from
    (select c1, c, c2, c3 from tc) xx1;
0 rows inserted/updated/deleted
ij> -- Both sides of predicate reference aggregates.
select x1.c1 from
  (select count(*) from t1 union select count(*) from t2) x1 (c1),
  (select count(*) from t3 union select count(*) from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Both sides of predicate reference aggregates, and
-- predicate is pushed through to non-flattenable nested
-- subquery.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1) xx1
      union select count(*) from t2
    ) x1 (c1),
  (select count(*) from t3 union select count(*) from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Both sides of predicate reference aggregates, and
-- predicate is pushed through to non-flattenable nested
-- subquery that is in turn part of a nested union.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1 union select distinct j from t2) xx1
      union select count(*) from t2
  ) x1 (c1),
  (select count(*) from t3 union select count(*) from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Left side of predicate references base column, right side
-- references aggregate; predicate is pushed through to non-
-- flattenable nested subquery.
select x1.c1 from
  (select xx1.c from
    (select distinct c, c1 from tc) xx1
      union select count(*) from t2
    ) x1 (c1),
  (select count(*) from t3 union select count(*) from t4) x2 (c2) 
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Left side of predicate references base column, right side
-- references aggregate; predicate is pushed through to non-
-- flattenable nested subquery.
select x1.c1 from
  (select xx1.c from
    (select c, c1 from tc) xx1
      union select count(*) from t2
    ) x1 (c1),
  (select count(*) from t3 union select count(*) from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Left side of predicate references base column, right side
-- side references aggregate; predicate is pushed through to
-- a subquery in a nested union that has literals in its result
-- column.
select x1.z1 from
  (select xx1.c1, xx1.c2, xx1.c, xx1.c3 from
    (select c1, c2, c3, c from tc) xx1
      union select 'i','j',j,'i' from t2
  ) x1 (z1, z2, z3, z4),
  (select count(*) from t3 union select count (*) from t4) x2 (c2)
where x1.z3 = x2.c2;
Z1  
----
ij> -- Both sides of predicate reference base columns; predicate
-- predicate is pushed through to a subquery in a nested union
-- that has literals in its result column.
select x1.z1 from
  (select xx1.c1, xx1.c2, xx1.c, xx1.c3 from
    (select c1, c2, c3, c from tc) xx1
      union select 'i','j',j,'i' from t2
  ) x1 (z1, z2, z3, z4),
  (select a from t3 union select count (*) from t4) x2 (c2)
where x1.z3 = x2.c2;
Z1  
----
i   
i   
i   
ij> -- Same as previous query, but with aggregate/base column
-- in x2 switched.
select x1.z1 from
  (select xx1.c1, xx1.c2, xx1.c, xx1.c3 from
    (select c1, c2, c3, c from tc) xx1
      union select 'i','j',j,'i' from t2
  ) x1 (z1, z2, z3, z4),
  (select count(*) from t3 union select a from t4) x2 (c2)
where x1.z3 = x2.c2;
Z1  
----
ij> -- Left side references aggregate, right side references base
-- column; predicate is pushed to non-flattenable subquery
-- that is part of a nested union for which one child references
-- a base column and the other references an aggregate.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1) xx1
      union select count(*) from t2
  ) x1 (c1),
  (select a from t3 union select a from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
ij> -- Same as previous query, but both children of inner-most
-- union reference base columns.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1) xx1
      union select i from t2
  ) x1 (c1),
  (select a from t3 union select a from t4) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
1          
2          
3          
4          
ij> -- Left side references aggregate, right side references base
-- column; predicate is pushed to non-flattenable subquery
-- that is part of a nested union for which one child references
-- a base column and the other references an aggregate.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1) xx1
      union select count(*) from t2
  ) x1 (c1),
  (select i from t2 union select i from t1) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
5          
ij> -- Same as previous query, but one child of x2 references
-- a literal.
select x1.c1 from
  (select count(*) from
    (select distinct j from t1) xx1
      union select count(*) from t2
  ) x1 (c1),
  (select 1 from t2 union select i from t1) x2 (c2)
where x1.c1 = x2.c2;
C1         
-----------
5          
ij> -- Left side of predicate references a base column that is
-- deeply nested inside a subquery, a union, and a view,
-- the latter of which itself has a union between two
-- nested subqueries (whew).  And finally, the position of
-- the base column w.r.t the outer query (x1) is different
-- than it is with respect to inner view (vz).
select x1.z4 from
  (select z1, z4, z3 from vz
    union select '1', 4, '3' from t1
  ) x1 (z1, z4, z3),
  (select distinct j from t2 union select j from t1) x2 (c2)
where x1.z4 = x2.c2;
Z4         
-----------
4          
2          
4          
ij> -- Same as previous query but with a different nested
-- view (vz2) that is missing the nested union found
-- in vz.
select x1.z4 from
  (select z1, z4, z3 from vz2
    union select '1', 4, '3' from t1
  ) x1 (z1, z4, z3),
  (select distinct j from t2 union select j from t1) x2 (c2)
where x1.z4 = x2.c2;
Z4         
-----------
4          
ij> -- Cleanup from this set of tests.
drop view vz;
0 rows inserted/updated/deleted
ij> drop view vz2;
0 rows inserted/updated/deleted
ij> drop table tc;
0 rows inserted/updated/deleted
ij> -- Now bump up the size of tables T3 and T4 to the point where
-- use of indexes will cause optimizer to choose nested loop join
-- (and push predicates) instead of hash join.  The following
-- insertions put roughly 50,000 rows into T3 and into T4.
-- These numbers are somewhat arbitrary, but please note that
-- reducing the number of rows in these two tables could cause the
-- optimizer to choose to skip pushing and instead use a hash join
-- for some of the test queries.  That's not 'wrong' per se, but
-- it's not what we want to test here...
autocommit off;
ij> insert into t3 (a) values 21, 22, 23, 24, 25, 26, 27, 28, 29, 30;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 31, 32, 33, 34, 35, 36, 37, 38, 39, 40;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 41, 42, 43, 44, 45, 46, 47, 48, 49, 50;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 51, 52, 53, 54, 55, 56, 57, 58, 59, 60;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 61, 62, 63, 64, 65, 66, 67, 68, 69, 70;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 71, 72, 73, 74, 75, 76, 77, 78, 79, 80;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 81, 82, 83, 84, 85, 86, 87, 88, 89, 90;
10 rows inserted/updated/deleted
ij> insert into t3 (a) values 91, 92, 93, 94, 95, 96, 97, 98, 99, 100;
10 rows inserted/updated/deleted
ij> update t3 set b = 2 * a where a > 20;
80 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
80 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
80 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
160 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
240 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
400 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
640 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
1040 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
1680 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
2720 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
4400 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
7120 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
11520 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 20);
18640 rows inserted/updated/deleted
ij> insert into t4 (a, b) (select a,b from t3 where a > 20);
30160 rows inserted/updated/deleted
ij> insert into t3 (a, b) (select a,b from t4 where a > 60);
24400 rows inserted/updated/deleted
ij> commit;
ij> autocommit on;
ij> -- See exactly how many rows we inserted, for sanity.
select count(*) from t3;
1          
-----------
54579      
ij> select count(*) from t4;
1          
-----------
48812      
ij> -- At this point we create the indexes.  Note that we intentionally
-- create the indexes AFTER loading the data, in order ensure that the
-- index statistics are correct.  We need the stats to be correct in
-- order for the optimizer to choose the correct plan (i.e. to push the
-- join predicates where possible).
CREATE INDEX "APP"."T3_IX1" ON "APP"."T3" ("A");
0 rows inserted/updated/deleted
ij> CREATE INDEX "APP"."T3_IX2" ON "APP"."T3" ("B");
0 rows inserted/updated/deleted
ij> CREATE INDEX "APP"."T4_IX1" ON "APP"."T4" ("A");
0 rows inserted/updated/deleted
ij> CREATE INDEX "APP"."T4_IX2" ON "APP"."T4" ("B");
0 rows inserted/updated/deleted
ij> -- Create the rest of objects used in this test.
CREATE TABLE "APP"."T5" ("I" INTEGER, "J" INTEGER);
0 rows inserted/updated/deleted
ij> insert into t5 values (5, 10);
1 row inserted/updated/deleted
ij> CREATE TABLE "APP"."T6" ("P" INTEGER, "Q" INTEGER);
0 rows inserted/updated/deleted
ij> insert into t5 values (2, 4), (4, 8);
2 rows inserted/updated/deleted
ij> CREATE TABLE "APP"."XX1" ("II" INTEGER NOT NULL, "JJ" CHAR(10),
  "MM" INTEGER, "OO" DOUBLE, "KK" BIGINT);
0 rows inserted/updated/deleted
ij> CREATE TABLE "APP"."YY1" ("II" INTEGER NOT NULL, "JJ" CHAR(10),
  "AA" INTEGER, "OO" DOUBLE, "KK" BIGINT);
0 rows inserted/updated/deleted
ij> ALTER TABLE "APP"."YY1" ADD CONSTRAINT "PK_YY1" PRIMARY KEY ("II");
0 rows inserted/updated/deleted
ij> ALTER TABLE "APP"."XX1" ADD CONSTRAINT "PK_XX1" PRIMARY KEY ("II");
0 rows inserted/updated/deleted
ij> create view xxunion as select all ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1 union all select ii, jj, kk, mm from xx1;
0 rows inserted/updated/deleted
ij> create view yyunion as select all ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1 union all select ii, jj, kk, aa from yy1;
0 rows inserted/updated/deleted
ij> -- And finally, run more extensive tests using the larger tables
-- that have indexes.  In these tests the optimizer should consider
-- pushing predicates where possible.  We can tell if a predicate
-- has been "pushed" by looking at the query plan information for
-- the tables in question: if the table has an index on a column that
-- is used as part of the pushed predicate, then the optimizer will
-- (for these tests) do an Index scan instead of a Table scan.  If
-- the table does not have such an index then the predicate will show
-- up as a "qualifier" for a Table scan.  In all of these tests T3 and
-- T4 have appropriate indexes, so if we push a pre