Returns a list of snapshots that are currently active.
|Column name||Data type||Description|
|connection_num||INT||The connection ID for the connection on which the snapshot is running.|
|start_sequence_num||UNSIGNED BIGINT||A unique number that identifies the snapshot.|
|statement_level||BIT||True if the snapshot was created with statement-snapshot or readonly-statement-snapshot. Otherwise, false.|
Several statement snapshots can exist on one connection. In the case of nested or interleaved statements running under statement snapshot isolation levels, each one begins a different statement snapshot with its first read or update.
Usually there is only one transaction snapshot per connection (one entry per connection in sa_snapshots with statement_level=0). However, a snapshot associated with a cursor never changes after the cursor's first fetch and a cursor opened WITH HOLD stays open through a commit or rollback. If the cursor has an associated snapshot, then the snapshot also persists. Therefore, it is possible for multiple transaction snapshots to exist for the same connection_num: one for the current transaction snapshot and one or more for old transaction snapshots that persist because of WITH HOLD cursors.
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