24.03.2017 7:53, Vlad Khorsun wrote: > 24.03.2017 1:29, Mark Rotteveel wrote: ... >> The column was created with a default, which means that existing rows will >> get that value, > > Engine doesn't assing values to a new field, i.e. there is no implicit > UPDATE of > the existing records. This is strong point of the engine, btw. > >> afaik it shouldn't change if the default >> later is changed. Is there a requirement in the SQL standard that supports >> your expectation? > > I doubt SQL standard describes Firebird multiversion metadata handling
-------------------------------- 11.11 <add column definition> Function Add a column to a table. Format <add column definition> ::= ADD [ COLUMN ] <column definition> ... General Rules 1) The column defined by the <column definition> is added to T. 2) Let C be the column added to T. Case: a) If C is a generated column, then let TN be the <table name> immediately contained in the containing <alter table statement>, let CN be the <column name> immediately contained in <column definition>, and let GE be the generation expression included in the column descriptor of C. The following <update statement: searched> is executed without further Syntax Rule or Access Rule checking: UPDATE TN SET CN = GE b) Otherwise, C is a base column. Case: i) If C is an identity column, then for each row in T let CS be the site corresponding to C and let NV be the result of applying the General Rules of Subclause 9.23, “Generation of the next value of a sequence generator”, with the sequence generator descriptor included in the column descriptor of C as SEQUENCE. Case: 1) If the declared type of C is a distinct type DIST, then let CNV be DIST(NV). 2) Otherwise, let CNV be NV. The General Rules of Subclause 9.2, “Store assignment”, are applied with CS as TARGET and CNV as VALUE. ... ii) Otherwise, every value in C is the default value for C. -------------------------------- I see that table is updated if generated or identity column is added. For other cases there is no such requirement. Regards, Vlad ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel