GS_GLOBAL_CHAIN

GS_GLOBAL_CHAIN records information about modification operations performed by users on the tamper-proof user table. Each record corresponds to a table-level modification operation. Users with the audit administrator permission can query this system catalog, but no user is allowed to modify this system catalog.

**Table 1** GS_GLOBAL_CHAIN columns
Name	Type	Description
blocknum	bigint	Block number, which is the sequence number of the current user operation recorded in the ledger.
dbname	name	Name of the database to which the modified tamper-proof user table belongs.
username	name	Username, which is the name of the user who performs the operation of modifying the user table.
starttime	timestamp with time zone	Time when a user performs an operation.
relid	oid	OID of the modified tamper-proof user table.
relnsp	name	Schema name, which is the name of the schema to which the modified tamper-proof user table belongs.
relname	name	User table name, which is the name of the modified tamper-proof user table.
relhash	hash16	Table-level hash change amount generated by operations.
globalhash	hash32	Global digest, which is calculated based on the information of the current row and the globalhash of the previous row. It connects the entire table to verify the integrity of GS_GLOBAL_CHAIN data.
txcommand	text	SQL statement whose operations are recorded.