box.space._session_settings
-
box.space.
_session_settings
¶ A temporary system space with settings that affect behavior, particularly SQL behavior, for the current session. It uses a special engine named „service“. Every „service“ tuple is created on the fly, that is, new tuples are made every time
_session_settings
is accessed. Every settings tuple has two fields:name
(the primary key) andvalue
. The tuples“ names and default values are:sql_default_engine
: default storage engine for new SQL tables. Default:memtx
.sql_full_column_names
: use full column names in SQL result set metadata. Default:false
.sql_full_metadata
: whether SQL result set metadata includes more than just name and type. Default:false
.sql_parser_debug
: show parser steps for following statements. Default:false
.sql_recursive_triggers
: whether a triggered statement can activate a trigger. Default:true
.sql_reverse_unordered_selects
: return result rows in reverse order if there is no ORDER BY clause. Default:false
.sql_select_debug
: show execution steps during SELECT. Default:false
.sql_seq_scan
: allow sequential scans in SQL SELECT. Default:true
.sql_vdbe_debug
: for internal use. Default:false
.sql_defer_foreign_keys
(removed in 2.11.0): whether foreign-key checks can wait till commit. Default:false
.error_marshaling_enabled
(removed in 2.10.0): whether error objects have a special structure. Default:false
.
Three requests are possible: select, get and update. For example, after
s = box.space._session_settings
,s:select('sql_default_engine')
probably returns{'sql_default_engine', 'memtx'}
, ands:update('sql_default_engine', {{'=', 'value', 'vinyl'}})
changes the default engine to „vinyl“.
Updatingsql_parser_debug
orsql_select_debug
orsql_vdbe_debug
has no effect unless Tarantool was built with-DCMAKE_BUILD_TYPE=Debug
. To check if this is so, look atrequire('tarantool').build.target
.