Document that ALTER TABLE .. TYPE removes statistics

Co-authored-by: Nikolai Berkoff 
Discussion: https://postgr.es/m/vCc8XnwDmlP4ZnHBQLIVxzD405BiYHVC9qZlhIF7IsfxK0gC9mZ4PUUOH0-3y6kv5p-87-3_ljqT1KvQVAnb8OoWhPU3kcqWn2ZpmxRBCQg=@pm.me

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 81291577f831d914514696260b6031dc9f3cb9c2..2d639a66af0e318cc0be23b92969a4d2a948a328 100644 (file)
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -198,6 +198,12 @@ WITH ( MODULUS numeric_literal, REM
       clause must be provided if there is no implicit or assignment
       cast from old to new type.
      
+
+     
+      When this form is used, the column's statistics are removed,
+      so running ANALYZE
+      on the table afterwards is recommended.
+