anchor.diff:  AUTOCOMMIT must be turned ON (the default) for the session.
   
   ```
  -CREATE [schema-class] SCHEMA schema-clause
  +CREATE [schema-class] SCHEMA [IF NOT EXISTS] schema-clause
   
   schema-class is:
      [ PRIVATE | SHARED ]
  
positive.code: AUTOCOMMIT must be turned ON (the default) for the session.
  
  ```
  DROP SCHEMA schema-name [RESTRICT|CASCADE]
  ```
  
  [[drop_schema_syntax]]
  
negative.code: any database user may add objects to the schema (SHARED). The default class is PRIVATE.
  +
  NOTE: Schemas created in {project-name} Release 0.9 or earlier are SHARED schemas.
  
  * `IF NOT EXISTS`
  +
  creates the schema if it does not already exist. If omitted, then an error will be raised if the schema
  already exists.
  
  * `_schema-name_`
  +
  