AWS aurora-dsql documentation change
Summary
Restructured ALTER TABLE documentation with expanded syntax support, added detailed descriptions of parameters, and reorganized sections into 'Supported syntax', 'Description', and 'Parameters'. Added new operations like DROP DEFAULT, DROP NOT NULL, DROP EXPRESSION, and identity column management.
Security assessment
Changes focus on syntax expansion and documentation reorganization without addressing vulnerabilities or security features. Added notes about identity column implementation requirements (e.g., explicit CACHE values) relate to performance/functionality, not security. No evidence of patching vulnerabilities or introducing security controls.
Diff
diff --git a/aurora-dsql/latest/userguide/alter-table-syntax-support.md b/aurora-dsql/latest/userguide/alter-table-syntax-support.md index 7359ea2d5..1a4b22e0b 100644 --- a//aurora-dsql/latest/userguide/alter-table-syntax-support.md +++ b//aurora-dsql/latest/userguide/alter-table-syntax-support.md @@ -7 +7 @@ -Storage modeIdentity column actionsAdd constraint actions +Supported syntaxDescriptionParameters @@ -12,0 +13,2 @@ Storage modeIdentity column actionsAdd constraint actions +## Supported syntax + @@ -28,2 +30,5 @@ Storage modeIdentity column actionsAdd constraint actions - ADD table_constraint_using_index - ALTER [ COLUMN ] column_name SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT } + ALTER [ COLUMN ] column_name SET DEFAULT expression + ALTER [ COLUMN ] column_name DROP DEFAULT + ALTER [ COLUMN ] column_name DROP NOT NULL + ALTER [ COLUMN ] column_name DROP EXPRESSION [ IF EXISTS ] + ALTER [ COLUMN ] column_name ADD GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ] @@ -31,0 +37,3 @@ Storage modeIdentity column actionsAdd constraint actions + ALTER [ COLUMN ] column_name SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT } + ADD table_constraint_using_index + DROP CONSTRAINT [ IF EXISTS ] constraint_name [ RESTRICT | CASCADE ] @@ -39 +47 @@ Storage modeIdentity column actionsAdd constraint actions -## Storage mode +## Description @@ -41 +49 @@ Storage modeIdentity column actionsAdd constraint actions -**`SET STORAGE`** +**`ADD [ COLUMN ] [ IF NOT EXISTS ]`** @@ -44 +52,6 @@ Storage modeIdentity column actionsAdd constraint actions -This form sets the storage mode for a column. For details on the available storage modes, see [Storage mode](./create-table-syntax-support.html#create-table-storage) on the [CREATE TABLE](./create-table-syntax-support.html) page. +This form adds a new column to the table, using the same syntax as [CREATE TABLE](./create-table-syntax-support.html). If `IF NOT EXISTS` is specified and a column already exists with this name, no error is thrown. + +**`SET`/`DROP DEFAULT`** + + +These forms set or remove the default value for a column (where removal is equivalent to setting the default value to NULL). The new default value will only apply in subsequent `INSERT` or `UPDATE` commands; it does not cause rows already in the table to change. @@ -46 +59 @@ This form sets the storage mode for a column. For details on the available stora -## Identity column actions +**`DROP NOT NULL`** @@ -48 +61,11 @@ This form sets the storage mode for a column. For details on the available stora -**`SET GENERATED{ ALWAYS | BY DEFAULT }` / `SET `sequence_option`` / `RESTART`** + +This form changes a column to allow null values. + +**`DROP EXPRESSION [ IF EXISTS ]`** + + +This form turns a stored generated column into a normal base column. Existing data in the columns is retained, but future changes will no longer apply the generation expression. If `DROP EXPRESSION IF EXISTS` is specified and the column is not a generated column, no error is thrown. In this case a notice is issued instead. + +**`ADD GENERATED{ ALWAYS | BY DEFAULT } AS IDENTITY`** +**`SET GENERATED{ ALWAYS | BY DEFAULT }`** +**`DROP IDENTITY [ IF EXISTS ]`** @@ -55 +78,3 @@ The `sequence_option` is an option supported by [ALTER SEQUENCE](./alter-sequenc -**`DROP IDENTITY [ IF EXISTS ]`** +###### Note + +Amazon Aurora DSQL requires an explicit `CACHE` value when using `ADD GENERATED AS IDENTITY`. Additionally, identity columns are only supported on `bigint` columns. @@ -56,0 +82 @@ The `sequence_option` is an option supported by [ALTER SEQUENCE](./alter-sequenc +When using identity columns, the cache value should be carefully considered. For more information, see the Important callout on the [CREATE SEQUENCE](./create-sequence-syntax-support.html) page. @@ -58 +84 @@ The `sequence_option` is an option supported by [ALTER SEQUENCE](./alter-sequenc -This form removes the identity property from a column. If `DROP IDENTITY IF EXISTS` is specified and the column is not an identity column, no error is thrown. In this case a notice is issued instead. +For guidance on how best to use identity columns based on workload patterns, see [Working with sequences and identity columns](./sequences-identity-columns-working-with.html). @@ -60 +86,4 @@ This form removes the identity property from a column. If `DROP IDENTITY IF EXIS -## Add constraint actions +**`SET STORAGE{ PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT }`** + + +This form sets the storage mode for a column. For details on the available storage modes, see [Storage mode](./create-table-syntax-support.html#create-table-storage) on the [CREATE TABLE](./create-table-syntax-support.html) page. @@ -72,0 +102,81 @@ After this command is executed, the index is "owned" by the constraint, in the s +**`DROP CONSTRAINT [ IF EXISTS ]`** + + +This form drops the specified constraint on a table, along with any index underlying the constraint. If `IF EXISTS` is specified and the constraint does not exist, no error is thrown. In this case a notice is issued instead. + +###### Important + +Currently, adding a new constraint is supported with the `CREATE TABLE` expression. `ALTER TABLE ADD CONSTRAINT` (mirroring support for `DROP CONSTRAINT`) is not yet available. If you have questions about this upcoming feature, please contact AWS Support or reach out directly via the [DSQL Public Discord](https://discord.com/invite/nEF6ksFWru). + +**`OWNER TO`** + + +This form changes the owner of the table to the specified user. + +**`RENAME`** + + +The `RENAME` forms change the name of a table, the name of an individual column in a table, or the name of a constraint of the table. When renaming a constraint that has an underlying index, the index is renamed as well. There is no effect on the stored data. + +**`SET SCHEMA`** + + +This form moves the table into another schema. Associated indexes, constraints, and sequences owned by table columns are moved as well. + +## Parameters + +**`IF EXISTS`** + + +Do not throw an error if the table does not exist. A notice is issued in this case. + +**`name`** + + +The name (optionally schema-qualified) of an existing table to alter. If `ONLY` is specified before the table name, only that table is altered. If `ONLY` is not specified, the table and all its descendant tables (if any) are altered. Optionally, `*` can be specified after the table name to explicitly indicate that descendant tables are included. + +**`column_name`** + + +Name of a new or existing column. + +**`new_column_name`** + + +New name for an existing column. + +**`new_name`** + + +New name for the table. + +**`data_type`** + + +Data type of the new column. + +**`constraint_name`** + + +Name of a new or existing constraint. + +**`CASCADE`** + + +Automatically drop objects that depend on the dropped constraint (for example, views referencing the column), and in turn all objects that depend on those objects. + +**`RESTRICT`** + + +Refuse to drop the constraint if there are any dependent objects. This is the default behavior. + +**`new_owner`** + + +The user name of the new owner of the table. + +**`new_schema`** + + +The name of the schema to which the table will be moved. +