sysvars

Documentation

Index

• Variables
• func GetInterestingVariables() []string
• func IsVitessAware(sysv string) bool
• type StorageCase
• type SystemVariable

Variables

var (
	ForeignKeyChecks = "foreign_key_checks"

	Autocommit                  = SystemVariable{Name: "autocommit", IsBoolean: true, Default: on}
	Charset                     = SystemVariable{Name: "charset", Default: utf8mb4, IdentifierAsString: true}
	ClientFoundRows             = SystemVariable{Name: "client_found_rows", IsBoolean: true, Default: off}
	SessionEnableSystemSettings = SystemVariable{Name: "enable_system_settings", IsBoolean: true, Default: on}
	Names                       = SystemVariable{Name: "names", Default: utf8mb4, IdentifierAsString: true}
	SessionUUID                 = SystemVariable{Name: "session_uuid", IdentifierAsString: true}
	SkipQueryPlanCache          = SystemVariable{Name: "skip_query_plan_cache", IsBoolean: true, Default: off}
	Socket                      = SystemVariable{Name: "socket", Default: off}
	SQLSelectLimit              = SystemVariable{Name: "sql_select_limit", Default: off, SupportSetVar: true}
	TransactionMode             = SystemVariable{Name: "transaction_mode", IdentifierAsString: true}
	TransactionReadOnly         = SystemVariable{Name: "transaction_read_only", IsBoolean: true, Default: off}
	TxReadOnly                  = SystemVariable{Name: "tx_read_only", IsBoolean: true, Default: off}
	Workload                    = SystemVariable{Name: "workload", IdentifierAsString: true}
	QueryTimeout                = SystemVariable{Name: "query_timeout"}

	// Online DDL
	DDLStrategy      = SystemVariable{Name: "ddl_strategy", IdentifierAsString: true}
	MigrationContext = SystemVariable{Name: "migration_context", IdentifierAsString: true}

	// Version
	Version        = SystemVariable{Name: "version"}
	VersionComment = SystemVariable{Name: "version_comment"}

	// Read After Write settings
	ReadAfterWriteGTID    = SystemVariable{Name: "read_after_write_gtid"}
	ReadAfterWriteTimeOut = SystemVariable{Name: "read_after_write_timeout"}
	SessionTrackGTIDs     = SystemVariable{Name: "session_track_gtids", IdentifierAsString: true}

	VitessAware = []SystemVariable{
		Autocommit,
		ClientFoundRows,
		SkipQueryPlanCache,
		TxReadOnly,
		TransactionReadOnly,
		SQLSelectLimit,
		TransactionMode,
		DDLStrategy,
		Workload,
		Charset,
		Names,
		SessionUUID,
		MigrationContext,
		SessionEnableSystemSettings,
		ReadAfterWriteGTID,
		ReadAfterWriteTimeOut,
		SessionTrackGTIDs,
		QueryTimeout,
	}

	ReadOnly = []SystemVariable{
		Socket,
		Version,
		VersionComment,
	}

	IgnoreThese = []SystemVariable{
		{Name: "big_tables", IsBoolean: true, SupportSetVar: true},
		{Name: "bulk_insert_buffer_size", SupportSetVar: true},
		{Name: "debug"},
		{Name: "default_storage_engine"},
		{Name: "default_tmp_storage_engine", SupportSetVar: true},
		{Name: "innodb_strict_mode", IsBoolean: true},
		{Name: "innodb_support_xa", IsBoolean: true},
		{Name: "innodb_table_locks", IsBoolean: true},
		{Name: "innodb_tmpdir"},
		{Name: "join_buffer_size", SupportSetVar: true},
		{Name: "keep_files_on_create", IsBoolean: true},
		{Name: "lc_messages"},
		{Name: "long_query_time"},
		{Name: "low_priority_updates", IsBoolean: true},
		{Name: "max_delayed_threads"},
		{Name: "max_insert_delayed_threads"},
		{Name: "multi_range_count"},
		{Name: "net_buffer_length"},
		{Name: "new", IsBoolean: true},
		{Name: "query_cache_type"},
		{Name: "query_cache_wlock_invalidate", IsBoolean: true},
		{Name: "query_prealloc_size"},
		{Name: "sql_buffer_result", IsBoolean: true, SupportSetVar: true},
		{Name: "transaction_alloc_block_size"},
		{Name: "wait_timeout"},
	}

	NotSupported = []SystemVariable{
		{Name: "audit_log_read_buffer_size"},
		{Name: "auto_increment_increment", SupportSetVar: true},
		{Name: "auto_increment_offset", SupportSetVar: true},
		{Name: "binlog_direct_non_transactional_updates"},
		{Name: "binlog_row_image"},
		{Name: "binlog_rows_query_log_events"},
		{Name: "innodb_ft_enable_stopword"},
		{Name: "innodb_ft_user_stopword_table"},
		{Name: "max_points_in_geometry", SupportSetVar: true},
		{Name: "max_sp_recursion_depth"},
		{Name: "myisam_repair_threads"},
		{Name: "myisam_sort_buffer_size"},
		{Name: "myisam_stats_method"},
		{Name: "ndb_allow_copying_alter_table"},
		{Name: "ndb_autoincrement_prefetch_sz"},
		{Name: "ndb_blob_read_batch_bytes"},
		{Name: "ndb_blob_write_batch_bytes"},
		{Name: "ndb_deferred_constraints"},
		{Name: "ndb_force_send"},
		{Name: "ndb_fully_replicated"},
		{Name: "ndb_index_stat_enable"},
		{Name: "ndb_index_stat_option"},
		{Name: "ndb_join_pushdown"},
		{Name: "ndb_log_bin"},
		{Name: "ndb_log_exclusive_reads"},
		{Name: "ndb_row_checksum"},
		{Name: "ndb_use_exact_count"},
		{Name: "ndb_use_transactions"},
		{Name: "ndbinfo_max_bytes"},
		{Name: "ndbinfo_max_rows"},
		{Name: "ndbinfo_show_hidden"},
		{Name: "ndbinfo_table_prefix"},
		{Name: "old_alter_table"},
		{Name: "preload_buffer_size"},
		{Name: "rbr_exec_mode"},
		{Name: "sql_log_off"},
		{Name: "thread_pool_high_priority_connection"},
		{Name: "thread_pool_prio_kickup_timer"},
		{Name: "transaction_write_set_extraction"},
	}
	UseReservedConn = []SystemVariable{
		{Name: "default_week_format"},
		{Name: "end_markers_in_json", IsBoolean: true, SupportSetVar: true},
		{Name: "eq_range_index_dive_limit", SupportSetVar: true},
		{Name: "explicit_defaults_for_timestamp"},
		{Name: ForeignKeyChecks, IsBoolean: true, SupportSetVar: true},
		{Name: "group_concat_max_len", SupportSetVar: true},
		{Name: "information_schema_stats_expiry"},
		{Name: "max_heap_table_size", SupportSetVar: true},
		{Name: "max_seeks_for_key", SupportSetVar: true},
		{Name: "max_tmp_tables"},
		{Name: "min_examined_row_limit"},
		{Name: "old_passwords"},
		{Name: "optimizer_prune_level", SupportSetVar: true},
		{Name: "optimizer_search_depth", SupportSetVar: true},
		{Name: "optimizer_switch", SupportSetVar: true},
		{Name: "optimizer_trace"},
		{Name: "optimizer_trace_features"},
		{Name: "optimizer_trace_limit"},
		{Name: "optimizer_trace_max_mem_size"},
		{Name: "optimizer_trace_offset"},
		{Name: "parser_max_mem_size"},
		{Name: "profiling", IsBoolean: true},
		{Name: "profiling_history_size"},
		{Name: "query_alloc_block_size"},
		{Name: "range_alloc_block_size", SupportSetVar: true},
		{Name: "range_optimizer_max_mem_size", SupportSetVar: true},
		{Name: "read_buffer_size", SupportSetVar: true},
		{Name: "read_rnd_buffer_size", SupportSetVar: true},
		{Name: "show_create_table_verbosity", IsBoolean: true},
		{Name: "show_old_temporals", IsBoolean: true},
		{Name: "sort_buffer_size", SupportSetVar: true},
		{Name: "sql_big_selects", IsBoolean: true, SupportSetVar: true},
		{Name: "sql_mode", SupportSetVar: true},
		{Name: "sql_notes", IsBoolean: true},
		{Name: "sql_quote_show_create", IsBoolean: true},
		{Name: "sql_safe_updates", IsBoolean: true, SupportSetVar: true},
		{Name: "sql_warnings", IsBoolean: true},
		{Name: "time_zone"},
		{Name: "tmp_table_size", SupportSetVar: true},
		{Name: "transaction_isolation", Case: SCUpper},
		{Name: "transaction_prealloc_size"},
		{Name: "tx_isolation", Case: SCUpper},
		{Name: "unique_checks", IsBoolean: true, SupportSetVar: true},
		{Name: "updatable_views_with_limit", IsBoolean: true, SupportSetVar: true},
	}
	CheckAndIgnore = []SystemVariable{

		{Name: "binlog_format"},
		{Name: "block_encryption_mode"},
		{Name: "character_set_client"},
		{Name: "character_set_connection"},
		{Name: "character_set_database"},
		{Name: "character_set_filesystem"},
		{Name: "character_set_results"},
		{Name: "character_set_server"},
		{Name: "collation_connection"},
		{Name: "collation_database"},
		{Name: "collation_server"},
		{Name: "completion_type"},
		{Name: "div_precision_increment", SupportSetVar: true},
		{Name: "innodb_lock_wait_timeout"},
		{Name: "interactive_timeout"},
		{Name: "lc_time_names"},
		{Name: "lock_wait_timeout", SupportSetVar: true},
		{Name: "max_allowed_packet"},
		{Name: "max_error_count", SupportSetVar: true},
		{Name: "max_execution_time", SupportSetVar: true},
		{Name: "max_join_size", SupportSetVar: true},
		{Name: "max_length_for_sort_data", SupportSetVar: true},
		{Name: "max_sort_length", SupportSetVar: true},
		{Name: "max_user_connections"},
		{Name: "net_read_timeout"},
		{Name: "net_retry_count"},
		{Name: "net_write_timeout"},
		{Name: "session_track_schema", IsBoolean: true},
		{Name: "session_track_state_change", IsBoolean: true},
		{Name: "session_track_system_variables"},
		{Name: "session_track_transaction_info"},
		{Name: "sql_auto_is_null", IsBoolean: true, SupportSetVar: true},
		{Name: "version_tokens_session"},
	}
)

System Settings

Functions

func GetInterestingVariables

func GetInterestingVariables() []string

GetInterestingVariables is used to return all the variables that may be listed in a SHOW VARIABLES command.

func IsVitessAware

func IsVitessAware(sysv string) bool

Types

type StorageCase

type StorageCase int

const (
	SCSame StorageCase = iota
	SCUpper
	SCLower
)

type SystemVariable

type SystemVariable struct {
	// IsBoolean is used to signal necessary type coercion so that strings
	// and numbers can be evaluated to a boolean value
	IsBoolean bool

	// IdentifierAsString allows identifiers (a.k.a. ColName) from the AST to be handled as if they are strings.
	// SET transaction_mode = two_pc => SET transaction_mode = 'two_pc'
	IdentifierAsString bool

	// Default is the default value, if none is given
	Default string

	Name string

	SupportSetVar bool

	Case StorageCase
}

SystemVariable is a system variable that Vitess handles in queries such as: select @@sql_mode set skip_query_plan_cache = true