ae-rules.md

Alter Executor

Validator rules:

Configuration

• NoAutoincrementOnTableRule (autorepair) - disallowed changing autoincrement value
• NoCharsetOnTablesRule (autorepair) - charset should come from parent configuration (database)
• NoCollationOnTablesRule (autorepair) - collation sould come from parent configuration (database)
• OnlyAsciiCharsetOnColumnRule - ascii charset is allowed for tokens, ids etc. (non-native languge data; faster comparations)
• OnlyAsciiCollationOnColumnRule - ascii_cs collation is allowed for tokens, ids etc. (non-native languge data; faster comparations)

Context

• ColumnExistsRule - validates that referred column exists
• ConstraintExistsRule - validates that referred constraint exists
• IndexExistsRule - validated that referred index exists
• TableExistsRule - validates that referred table exists

Defaults

• DroppedColumnHasDefaultValueRule - ensures that column has been previously correctly removed from all INSERT queries
• NewColumnHasDefaultValueRule - ensures that previously existing INSERT queries will not start failing
• OnlyNullDefaultValueRule - non-null default values shoul be defined by application, not in database schema

Foreign keys

• AlwaysOnUpdateCascadeRule (autorepair) - ensures cascade rule is not ommitted
• AlwaysOnDeleteRule - ensures cascade rule is not ommitted
• CannotRecreateForeignKeyWithSameNameRule - cannot be done in one transaction (limitation of MySQL)
• IndexExistsForForeignKeyRule - ensures a properly named index is created for foreign key
• NoAutoincrementOnForeignKeyColumnsRule - ???
• SetForeignKeyCheckOffBeforeAddingNewForeignKeyRule - do not check existing data (faster; usually a new column or table)

Indexes

• NoDuplicitIndexesRule - disallow duplicit prefixes for multi-column indexes (can save a lot data without affecting speed)
• NoNullableColumnsInMultiColumnUniqueKeysRule - null in unique keys behaves quite unexpectadly because null != null
• PrimaryKeyRule - enforces explicit primary key
• StringIndexesLengthRule - limit length of string indexes (indexes create fixed length allocations 3x the size of column length for utf8 and 4x for utf8mb4)

Locking

• AlterAlgorithmRule (autorepair) - detects the minimal locking algorithm for ALTER (+warnings)
• AlterLockRule (autorepair) - detexts the minimal locking algorithm for ALTER (+warnings)

Naming

• IndexNameRule (autorepair) - standardized index naming
• ForeignKeyConstraintNameRule (autorepair) - standardized FK naming
• SystemVariablesSpellingRule - checks if variable exists

Privileges

• OnlyAllowedCommandsRule - disallowes non-whitelisted commands in migrations

Readability

• ChangeColumnSimplestWayRule (autorepair) - validate that column is change by minimal boilerplate command - most understandable what is going on (from ALTER COLUMN, MODIFY COLUMN, RENAME COLUMN...)

Types

• CharCharsetRule - enforces charset for fixed length strings (ascii for ids and tokens)
• DisallowedTypesRule - disallowes enum and set (should be defined by application)
• NoAutoincrementRule - disallowes autoincrement (rule for new tables where uuid is preferred)
• NoSizeParameterOnIntAndFloatRule (autorepair) - disallowes deprecated params for formatting
• PrimaryKeysAllowedTypesRule - disallowes some types in PK (only int and char allowed)
• UnsignedNumbersRule (autorepair) - warnings for signed
• UnsignedPrimaryKeysRule (autorepair) - disallowes signed columns in PK

Syntax

• InvalidCommandRule - syntax error catch-all