barak/cayley
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Fix a deadlock behavior with DELETE transactions

Browse source 
It appears that preparing an INSERT statement on PostgreSQL actually makes it expecting to receive INSERTs and thus, it create some kind of locks for it. If instead, you only send him DELETE statements, it will indefinitely wait for an INSERT and will hung.
This commit is contained in:
Quentin Machu 2015-11-17 20:31:40 -05:00
parent cfbc0b3649
commit d874441431
1 changed files with 2 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

10
graph/sql/quadstore.go
View file

@ -192,16 +192,10 @@ func (qs *QuadStore) runTxPostgres(tx *sql.Tx, in []graph.Delta, opts graph.Igno
return qs.copyFrom(tx, in)
}
insert, err := tx.Prepare(`INSERT INTO quads(subject, predicate, object, label, id, ts, subject_hash, predicate_hash, object_hash, label_hash) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)`)
defer insert.Close()
if err != nil {
glog.Errorf("Cannot prepare insert statement: %v", err)
return err
}
for _, d := range in {
switch d.Action {
case graph.Add:
_, err := insert.Exec(
_, err := tx.Exec(`INSERT INTO quads(subject, predicate, object, label, id, ts, subject_hash, predicate_hash, object_hash, label_hash) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10);`,
d.Quad.Subject,
d.Quad.Predicate,
d.Quad.Object,
@ -214,7 +208,7 @@ func (qs *QuadStore) runTxPostgres(tx *sql.Tx, in []graph.Delta, opts graph.Igno
hashOf(d.Quad.Label),
)
if err != nil {
glog.Errorf("couldn't prepare INSERT statement: %v", err)
glog.Errorf("couldn't exec INSERT statement: %v", err)
return err
}
case graph.Delete: