gistfile1.txt

Session 1:

DROP TABLE IF EXISTS test_drop_concurrently ;
CREATE TABLE test_drop_concurrently(id serial primary key, data int);
INSERT INTO test_drop_concurrently(data) SELECT * FROM generate_series(1,
100);
CREATE INDEX test_drop_concurrently_data ON test_drop_concurrently(data);

SET enable_seqscan = false;

PREPARE getrow_idx AS SELECT * FROM test_drop_concurrently WHERE data = 34;
PREPARE getrow_seq AS SELECT * FROM test_drop_concurrently WHERE data::text = 34::text;

BEGIN;
EXPLAIN (ANALYZE, COSTS off) EXECUTE getrow_idx;
EXPLAIN (ANALYZE, COSTS off) EXECUTE getrow_seq;
(1 row)

Session 2:
BEGIN;
SELECT * FROM test_drop_concurrently WHERE data = 34;

Session 3:
DROP INDEX CONCURRENTLY test_drop_concurrently_data;
(in-progress)

Session 2:
INSERT INTO test_drop_concurrently(data) SELECT * FROM generate_series(1,
100);
COMMIT;

Session 1:
EXPLAIN (ANALYZE, COSTS off) EXECUTE getrow_idx;
EXPLAIN (ANALYZE, COSTS off) EXECUTE getrow_seq;
(2 rows)