devops/postgres/tools/removeUnusedNgrams.sql

   1
   2 WITH listed AS
   3   ( select nn.ngrams_id AS id, count(*) AS c
   4     FROM node_node_ngrams nn
   5     GROUP BY nn.ngrams_id
   6   )
   7
   8 --SELECT count(*) from listed l
   9 -- WHERE
  10 --l.c <= 1
  11
  12
  13 DELETE FROM ngrams n
  14   USING listed l
  15   WHERE
  16   n.id = l.id
  17   AND l.c <= 1
  18 ;
  19
  20
  21