The `pgmemento.table_event_log` table stores metadata about different kind of events happening during one transaction against one table. Like transactions, they are inserted by the `pgmemento.log_table_event` function called from [table triggers](https://github.com/pgMemento/pgMemento/wiki/DML-logging) or [event trigger](https://github.com/pgMemento/pgMemento/wiki/DDL-logging). Each event type is only logged once per transaction and statement timestamp per table. There is UNIQUE index defined on the event_key column which concatenates the timestamp timestamp with values from columns `stmt_time`, the internal txid, the `op_id`, `table_name` and `schema_name`. The log table contains the following columns:
* `id SERIAL`: The Primary Key
* `transaction_id INTEGER NOT NULL`: Foreign Key to `transaction_log` table
* `stmt_time TIMESTAMP WITH TIME ZONE`: Stores the result of statement_timestamp() function
* `op_id SMALLINT NOT NULL`: ID of event type
* `table_operation TEXT`: Text for of event type
* `table_name TEXT NOT NULL`: Name of table that fired the trigger
* `schema_name TEXT NOT NULL`: Schema of firing table
* `event_key TEXT`: Concatenated information of most columns to join with row-based logs