Add DDL statements to create Iceberg branches and tags about presto

[s-akhtar-baig]

@tdcmeehan, I have compiled a list of statements for various scenarios based on your proposed syntax and Iceberg spec. Let me know what you think.

Notes:

1. Default retention policy: undefined period of time
2. Default snapshot: current snapshot
3. Snapshot retention: sets the minimum number of snapshots to retain on a branch and/or the maximum age of individual snapshots to retain on the branch.

Syntax for branches

1. Create branch with default values: ALTER TABLE iceberg.default.mytable CREATE BRANCH 'audit-branch'
2. Create branch as of version: ALTER TABLE iceberg.default.mytable CREATE BRANCH 'audit-branch' FOR SYSTEM_VERSION AS OF 3
3. Create branch as of timestamp: ALTER TABLE iceberg.default.mytable CREATE BRANCH 'audit-branch' FOR SYSTEM_TIME AS OF TIMESTAMP ‘2024-03-02 13:29:46.822 America/Los_Angeles‘
4. Create branch with retention policy: ALTER TABLE iceberg.default.mytable CREATE BRANCH 'audit-branch' FOR SYSTEM_VERSION AS OF 3 RETAIN 7 DAYS
5. Create branch with snapshots retention: ALTER TABLE iceberg.default.mytable CREATE BRANCH 'audit-branch' FOR SYSTEM_VERSION AS OF 3 RETAIN 7 DAYS WITH SNAPSHOT RETENTION 2 SNAPSHOTS 2 DAYS

Syntax for tags

1. Create tag with default values: ALTER TABLE iceberg.default.mytable CREATE TAG 'audit-tag'
2. Create tag as of version: ALTER TABLE iceberg.default.mytable CREATE TAG 'audit-tag' FOR SYSTEM_VERSION AS OF 3
3. Create tag as of timestamp: ALTER TABLE iceberg.default.mytable CREATE TAG 'audit-tag' FOR SYSTEM_TIME AS OF TIMESTAMP ‘2024-03-02 13:29:46.822 America/Los_Angeles‘
4. Create tag with retention policy: ALTER TABLE iceberg.default.mytable CREATE TAG 'audit-tag' FOR SYSTEM_VERSION AS OF 3 RETAIN 7 DAYS

[tdcmeehan]

@s-akhtar-baig looks good to me, except retention policy examples don't seem to need to include SYSTEM_TIME/SYSTEM_VERSION (since they don't specify a time or version).

CC some other folks who may be interested in syntax discussions: @rschlussel @aditi-pandit @kaikalur @ClarenceThreepwood

[s-akhtar-baig]

Oh yes, my bad! I have updated the two statements.