Database header page information: Flags 0 Checksum 12345 Generation 184 Page size 4096 ODS version described below: Flags Flags are not used on a database header page. Checksum All checksums are 12345. Checksums on the various database pages are no longer used. Generation The generation number is

If from is longer than to, occurrences of the extra characters in from are removed. translate(’12345’, ’143’, ’ax’) a2x5 The concat, concat_ws and format functions are variadic, so it is possible to 00 WHERE acctnum = 12345; UPDATE accounts SET balance = balance - 100.00 WHERE acctnum = 7534; COMMIT; If two such transactions concurrently try to change the balance of account 12345, we clearly want the FROM foo WHERE id = 12345; -- ok SELECT pg_advisory_lock(id) FROM foo WHERE id > 12345 LIMIT 100; -- danger! SELECT pg_advisory_lock(q.id) FROM ( SELECT id FROM foo WHERE id > 12345 LIMIT 100 ) q; -- ok

If from is longer than to, occurrences of the extra charac- ters in from are deleted. translate('12345', '143', 'ax') → a2x5 unistr ( text ) → text Evaluate escaped Unicode characters in the argument 00 WHERE acctnum = 12345; UPDATE accounts SET balance = balance - 100.00 WHERE acctnum = 7534; COMMIT; If two such transactions concurrently try to change the balance of account 12345, we clearly want the FROM foo WHERE id = 12345; -- ok SELECT pg_advisory_lock(id) FROM foo WHERE id > 12345 LIMIT 100; -- danger! SELECT pg_advisory_lock(q.id) FROM ( SELECT id FROM foo WHERE id > 12345 LIMIT 100 ) q; --

b = rdb$blob_util.new_blob(false, true); -- Add chunks of data. b = blob_append(b, '12345'); b = blob_append(b, '67'); suspend; end Open a BLOB and return chunks of it with EXECUTE READ COMMITTED, the snapshot number will move forward. Example SET TRANSACTION SNAPSHOT AT NUMBER 12345; SNAPSHOT TABLE STABILITY Isolation Level The SNAPSHOT TABLE STABILITY — or SNAPSHOT TABLE — isolation