Tony Brusseau created DERBY6093:

Summary: dramatically worse query plan for prepared stamement vs calling directly
Key: DERBY6093
URL: https://issues.apache.org/jira/browse/DERBY6093
Project: Derby
Issue Type: Bug
Components: Store
Affects Versions: 10.9.1.0
Environment: Linux
Reporter: Tony Brusseau
If I run a count query given all the parameters directly, then the query executes in .05s,
however, if I send it across as a prepared statement, then the query takes 40s to run (because
is does a complete table scan on a table with 15m rows).
The query looks like:
SELECT COUNT(*)
FROM KB.FORMULA_ENTRIES fe1, KB.FORMULA_ENTRIES fe2
WHERE
(fe1.arg_0_term = 1407374883620920) AND (fe1.arg_num = 1) AND (fe1.arg_term = 1407374883574780)
AND (fe1.formula_type = 0)
AND (fe1.formula_id = fe2.formula_id) AND (fe2.arg_0_term = 1407374883620920) AND (fe2.arg_num
= 2) AND (fe2.arg_term = 1407374883663337) AND (fe2.formula_type = 0)
or the prepared version like:
SELECT COUNT(*)
FROM KB.FORMULA_ENTRIES fe1
, KB.FORMULA_ENTRIES fe2
WHERE
(fe1.arg_0_term = ?) AND (fe1.arg_num = ?) AND (fe1.arg_term = ?) AND (fe1.formula_type =
?)
AND (fe1.formula_id = fe2.formula_id) AND (fe2.arg_0_term = ?) AND (fe2.arg_num = ?) AND (fe2.arg_term
= ?) AND (fe2.formula_type = ?)
The table is defined as:
DROP TABLE KB.FORMULA_ENTRIES;
CREATE TABLE KB.FORMULA_ENTRIES
(
formula_entries_id BIGINT NOT NULL,)
formula_id BIGINT NOT NULL,
arg_0_term BIGINT NOT NULL,
arg_term BIGINT NOT NULL,
arg_num INTEGER NOT NULL,
formula_type SMALLINT NOT NULL
);
ALTER TABLE kb.formula_entries ADD CONSTRAINT kb_formula_entries_pk PRIMARY KEY (formula_entries_id);
ALTER TABLE kb.formula_entries ADD CONSTRAINT kb_fomula_entries_formula_id_fk
FOREIGN KEY (formula_id) REFERENCES kb.formula_term (term_id) ON DELETE CASCADE;
CREATE INDEX kb_formula_entries_formula_term_type ON kb.formula_entries (arg_term, formula_type);
CREATE INDEX kb_formula_entries_formula_term_arg0_type ON kb.formula_entries (arg_term, arg_0_term,
formula_type);
CREATE INDEX kb_formula_entries_formula_term_num_type ON kb.formula_entries (arg_term, arg_num,
formula_type);
CREATE INDEX kb_formula_entries_formula_term_arg0_num_type ON kb.formula_entries (arg_term,
arg_0_term, arg_num, formula_type);
The good query plan looks (when *not* sent as a prepared statements) looks like:
Tue Feb 26 16:15:21 CST 2013 Thread[DRDAConnThread_5,5,main] (XID = 40971291), (SESSIONID
= 7), SELECT COUNT(*)
FROM KB.FORMULA_ENTRIES fe1, KB.FORMULA_ENTRIES fe2
WHERE
(fe1.arg_0_term = 1407374883620920) AND (fe1.arg_num = 1) AND (fe1.arg_term = 1407374883574780)
AND (fe1.formula_type = 0)
AND (fe1.formula_id = fe2.formula_id) AND (fe2.arg_0_term = 1407374883620920) AND (fe2.arg_num
= 2) AND (fe2.arg_term = 1407374883663337) AND (fe2.formula_type = 0) ******* ProjectRestrict
ResultSet (10):
Number of opens = 1
Rows seen = 1
Rows filtered = 0
restriction = false
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 1.00
optimizer estimated cost: 7184.99
Source result set:
Scalar Aggregate ResultSet:
Number of opens = 1
Rows input = 3863
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 7184.99
Index Key Optimization = false
Source result set:
ProjectRestrict ResultSet (9):
Number of opens = 1
Rows seen = 3863
Rows filtered = 0
restriction = false
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 7184.99
Source result set:
Nested Loop Join ResultSet:
Number of opens = 1
Rows seen from the left = 3863
Rows seen from the right = 3863
Rows filtered = 0
Rows returned = 3863
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 7184.99
Left result set:
ProjectRestrict ResultSet (5):
Number of opens = 1
Rows seen = 3865
Rows filtered = 2
restriction = true
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 35.89
optimizer estimated cost: 6785.98
Source result set:
Index Row to Base Row ResultSet for FORMULA_ENTRIES:
Number of opens = 1
Rows seen = 3865
Columns accessed from heap = {1, 2, 3, 4, 5}
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 35.89
optimizer estimated cost: 6785.98
Index Scan ResultSet for FORMULA_ENTRIES using index KB_FORMULA_ENTRIES_FORMULA_TERM_TYPE
at read committed isolation level using instantaneous share row locking chosen by the optimizer
Number of opens = 1
Rows seen = 3865
Rows filtered = 0
Fetch Size = 16
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
next time in milliseconds/row = 0
scan information:
Bit set of columns fetched=All
Number of columns fetched=3
Number of deleted rows visited=0
Number of pages visited=7
Number of rows qualified=3865
Number of rows visited=3866
Scan type=btree
Tree height=3
start position:
>= on first 2 column(s).
Ordered null semantics on the following columns:
0 1
stop position:
> on first 2 column(s).
Ordered null semantics on the following columns:
0 1
qualifiers:
None
optimizer estimated row count: 35.89
optimizer estimated cost: 6785.98
Right result set:
ProjectRestrict ResultSet (8):
Number of opens = 3863
Rows seen = 15452
Rows filtered = 11589
restriction = true
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 399.01
Source result set:
Index Row to Base Row ResultSet for FORMULA_ENTRIES:
Number of opens = 3863
Rows seen = 15452
Columns accessed from heap = {1, 2, 3, 4, 5}
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 399.01
Index Scan ResultSet for FORMULA_ENTRIES using constraint KB_FOMULA_ENTRIES_FORMULA_ID_FK
at read committed isolation level using instantaneous share row locking chosen by the optimizer
Number of opens = 3863
Rows seen = 15452
Rows filtered = 0
Fetch Size = 16
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
next time in milliseconds/row = 0
scan information:
Bit set of columns fetched=All
Number of columns fetched=2
Number of deleted rows visited=0
Number of pages visited=11606
Number of rows qualified=15452
Number of rows visited=19315
Scan type=btree
Tree height=3
start position:
>= on first 1 column(s).
Ordered null semantics on the following columns:
0
stop position:
> on first 1 column(s).
Ordered null semantics on the following columns:
0
qualifiers:
None
optimizer estimated row count: 0.00
optimizer estimated cost: 399.01
The bad query plan looks (when sent as a prepared statements) looks like:
Tue Feb 26 16:09:35 CST 2013 Thread[DRDAConnThread_4,5,main] (XID = 40971265), (SESSIONID
= 5), SELECT COUNT(*)
FROM KB.FORMULA_ENTRIES fe1
, KB.FORMULA_ENTRIES fe2
WHERE
(fe1.arg_0_term = ?) AND (fe1.arg_num = ?) AND (fe1.arg_term = ?) AND (fe1.formula_type =
?)
AND (fe1.formula_id = fe2.formula_id) AND (fe2.arg_0_term = ?) AND (fe2.arg_num = ?) AND (fe2.arg_term
= ?) AND (fe2.formula_type = ?) ******* ProjectRestrict ResultSet (9):
Number of opens = 1
Rows seen = 1
Rows filtered = 0
restriction = false
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 1.00
optimizer estimated cost: 43.36
Source result set:
Scalar Aggregate ResultSet:
Number of opens = 1
Rows input = 3863
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 43.36
Index Key Optimization = false
Source result set:
ProjectRestrict ResultSet (8):
Number of opens = 1
Rows seen = 3863
Rows filtered = 0
restriction = false
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 43.36
Source result set:
Nested Loop Join ResultSet:
Number of opens = 1
Rows seen from the left = 3863
Rows seen from the right = 3863
Rows filtered = 0
Rows returned = 3863
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 43.36
Left result set:
Index Row to Base Row ResultSet for FORMULA_ENTRIES:
Number of opens = 1
Rows seen = 3863
Columns accessed from heap = {1, 2, 3, 4, 5}
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 2.98
optimizer estimated cost: 10.89
Index Scan ResultSet for FORMULA_ENTRIES using index KB_FORMULA_ENTRIES_FORMULA_TERM_ARG0_NUM_TYPE
at read committed isolation level using instantaneous share row locking chosen by the optimizer
Number of opens = 1
Rows seen = 3863
Rows filtered = 0
Fetch Size = 16
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
next time in milliseconds/row = 0
scan information:
Bit set of columns fetched=All
Number of columns fetched=5
Number of deleted rows visited=0
Number of pages visited=8
Number of rows qualified=3863
Number of rows visited=3864
Scan type=btree
Tree height=3
start position:
>= on first 4 column(s).
Ordered null semantics on the following columns:
stop position:
> on first 4 column(s).
Ordered null semantics on the following columns:
qualifiers:
None
optimizer estimated row count: 2.98
optimizer estimated cost: 10.89
Right result set:
ProjectRestrict ResultSet (7):
Number of opens = 3863
Rows seen = 14922769
Rows filtered = 14918906
restriction = true
projection = true
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
restriction time (milliseconds) = 0
projection time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 32.47
Source result set:
Index Row to Base Row ResultSet for FORMULA_ENTRIES:
Number of opens = 3863
Rows seen = 14922769
Columns accessed from heap = {1, 2, 3, 4, 5}
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
optimizer estimated row count: 0.00
optimizer estimated cost: 32.47
Index Scan ResultSet for FORMULA_ENTRIES using index KB_FORMULA_ENTRIES_FORMULA_TERM_ARG0_NUM_TYPE
at read committed isolation level using instantaneous share row locking chosen by the optimizer
Number of opens = 3863
Rows seen = 14922769
Rows filtered = 0
Fetch Size = 16
constructor time (milliseconds) = 0
open time (milliseconds) = 0
next time (milliseconds) = 0
close time (milliseconds) = 0
next time in milliseconds/row = 0
scan information:
Bit set of columns fetched=All
Number of columns fetched=5
Number of deleted rows visited=0
Number of pages visited=34767
Number of rows qualified=14922769
Number of rows visited=14926632
Scan type=btree
Tree height=3
start position:
>= on first 4 column(s).
Ordered null semantics on the following columns:
stop position:
> on first 4 column(s).
Ordered null semantics on the following columns:
qualifiers:
None
optimizer estimated row count: 0.00
optimizer estimated cost: 32.47

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