src/bin/psql/crosstabview.h

   1 /*
   2  * psql - the PostgreSQL interactive terminal
   3  *
   4  * Copyright (c) 2000-2025, PostgreSQL Global Development Group
   5  *
   6  * src/bin/psql/crosstabview.h
   7  */
   8
   9 #ifndef CROSSTABVIEW_H
  10 #define CROSSTABVIEW_H
  11
  12 #include "libpq-fe.h"
  13
  14 /*
  15  * Limit the number of output columns generated in memory by the crosstabview
  16  * algorithm. A new output column is added for each distinct value found in the
  17  * column that pivots (to form the horizontal header).
  18  * The purpose of this limit is to fail early instead of over-allocating or spending
  19  * too much time if the crosstab to generate happens to be unreasonably large
  20  * (worst case: a NxN cartesian product with N=number of tuples).
  21  * The value of 1600 corresponds to the maximum columns per table in storage,
  22  * but it could be as much as INT_MAX theoretically.
  23  */
  24 #define CROSSTABVIEW_MAX_COLUMNS 1600
  25
  26 /* prototypes */
  27 extern bool PrintResultInCrosstab(const PGresult *res);
  28
  29 #endif                                                  /* CROSSTABVIEW_H */