| SELECT * FROM pgperf.snapshot_pg_current_xlog ORDER BY 1; |
| sid | location | insert_location |
| -----+----------+----------------- |
| (0 rows) |
| |
| SELECT pgperf.create_snapshot_pg_current_xlog(0); |
| create_snapshot_pg_current_xlog |
| --------------------------------- |
| t |
| (1 row) |
| |
| SELECT pgperf.create_snapshot_pg_current_xlog(1); |
| create_snapshot_pg_current_xlog |
| --------------------------------- |
| t |
| (1 row) |
| |
| WITH s0 AS ( |
| SELECT * FROM pgperf.snapshot_pg_current_xlog WHERE sid = 0 |
| ), s1 AS ( |
| SELECT * FROM pgperf.snapshot_pg_current_xlog WHERE sid = 1 |
| ) |
| SELECT s0.location < s1.location, s0.insert_location < s1.insert_location |
| FROM s0, s1 |
| WHERE s0.sid + 1 = s1.sid; |
| ?column? | ?column? |
| ----------+---------- |
| t | t |
| (1 row) |
| |
| SELECT count(*) FROM pgperf.snapshot_pg_current_xlog; |
| count |
| ------- |
| 2 |
| (1 row) |
| |
| SELECT pgperf.delete_snapshot_pg_current_xlog(1); |
| delete_snapshot_pg_current_xlog |
| --------------------------------- |
| t |
| (1 row) |
| |
| SELECT count(*) FROM pgperf.snapshot_pg_current_xlog; |
| count |
| ------- |
| 1 |
| (1 row) |
| |
| SELECT pgperf.delete_snapshot_pg_current_xlog(0); |
| delete_snapshot_pg_current_xlog |
| --------------------------------- |
| t |
| (1 row) |
| |
| SELECT count(*) FROM pgperf.snapshot_pg_current_xlog; |
| count |
| ------- |
| 0 |
| (1 row) |
| |