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Diffstat (limited to 'src/bin/psql/crosstabview.h')
| -rw-r--r-- | src/bin/psql/crosstabview.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/bin/psql/crosstabview.h b/src/bin/psql/crosstabview.h new file mode 100644 index 00000000000..3cb4d755890 --- /dev/null +++ b/src/bin/psql/crosstabview.h @@ -0,0 +1,26 @@ +/* + * psql - the PostgreSQL interactive terminal + * + * Copyright (c) 2000-2016, PostgreSQL Global Development Group + * + * src/bin/psql/crosstabview.h + */ + +#ifndef CROSSTABVIEW_H +#define CROSSTABVIEW_H + +/* + * Limit the number of output columns generated in memory by the crosstabview + * algorithm. A new output column is added for each distinct value found in the + * column that pivots (to form the horizontal header). + * The purpose of this limit is to fail early instead of over-allocating or spending + * too much time if the crosstab to generate happens to be unreasonably large + * (worst case: a NxN cartesian product with N=number of tuples). + * The value of 1600 corresponds to the maximum columns per table in storage, + * but it could be as much as INT_MAX theorically. + */ +#define CROSSTABVIEW_MAX_COLUMNS 1600 + +/* prototypes */ +extern bool PrintResultsInCrosstab(PGresult *res); +#endif /* CROSSTABVIEW_H */ |