2.1. Limitations of Shardman
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2.1. Limitations of Shardman

2.1.1. ALTER TABLE Limitations
2.1.2. CREATE TABLE Limitations
2.1.3. DROP TABLE Limitations
2.1.4. Limitations of Managing Global Roles
2.1.5. Other Limitations

To ensure consistency of a sharded database, Shardman imposes some restrictions on SQL commands executed.

2.1.1. ALTER TABLE Limitations

  • ALTER TABLE is prohibited for global tables.

  • ALTER TABLE is prohibited for partitions of sharded tables.

  • All forms of ALTER TABLE are prohibited for sharded tables except these:

    • ALTER TABLE OWNER is allowed, and it changes the owner of all partitions of the sharded table.

    • SET/DROP NOT NULL is allowed.

    • ADD COLUMN and DROP COLUMN are allowed except adding columns of serial types.

2.1.2. CREATE TABLE Limitations

  • All limitations for ALTER TABLE apply.

  • A temporary table cannot be created as sharded.

2.1.3. DROP TABLE Limitations

  • Sharded tables and local tables cannot be dropped in the same statement.

  • Partitions of a sharded table cannot be dropped.

2.1.4. Limitations of Managing Global Roles

  • Global roles cannot be renamed.

  • Global and local roles cannot be dropped in the same statement.

  • GRANT to a local and global role in the same statement is prohibited.

  • REVOKE from a local and global role in the same statement is prohibited.

2.1.5. Other Limitations

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Chapter 2. Developer Guide Home 2.2. Shardman Architecture