doc: Recommend ANALYZE after ALTER TABLE ... SET EXPRESSION AS. ALTER TABLE ... SET EXPRESSION AS removes statistics for the target column, so running ANALYZE afterward is recommended. But this was previously not documented, even though a similar recommendation exists for ALTER TABLE ... SET DATA TYPE, which also clears the column's statistics. This commit updates the documentation to include the ANALYZE recommendation for SET EXPRESSION AS.
Since v18, virtual generated columns are supported, and these columns never have statistics. Therefore, ANALYZE is not needed after SET DATA TYPE or SET EXPRESSION AS when used on virtual generated columns. This commit also updates the documentation to clarify that ANALYZE is unnecessary in such cases. Back-patch the ANALYZE recommendation for SET EXPRESSION AS to v17 where the feature was introduced, and the note about virtual generated columns to v18 where those columns were added. Author: Yugo Nagata <nag...@sraoss.co.jp> Reviewed-by: Fujii Masao <masao.fu...@gmail.com> Discussion: https://postgr.es/m/20250804151418.0cf365bd2855d60676344...@sraoss.co.jp Backpatch-through: 17 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/0b6aea03843dc75871b0490c6302a71a8fecb53d Modified Files -------------- doc/src/sgml/ref/alter_table.sgml | 11 +++++++++++ 1 file changed, 11 insertions(+)
