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Diffstat (limited to 'src/backend/utils/adt/misc.c')
-rw-r--r-- | src/backend/utils/adt/misc.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c new file mode 100644 index 00000000000..7ba7cc98f7e --- /dev/null +++ b/src/backend/utils/adt/misc.c @@ -0,0 +1,96 @@ +/*------------------------------------------------------------------------- + * + * misc.c-- + * + * + * Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * $Header: /cvsroot/pgsql/src/backend/utils/adt/misc.c,v 1.1.1.1 1996/07/09 06:22:04 scrappy Exp $ + * + *------------------------------------------------------------------------- + */ +#include <sys/file.h> +#include "postgres.h" +#include "utils/datum.h" +#include "catalog/pg_type.h" +#include "utils/builtins.h" + +#if !defined(PORTNAME_linux) && !defined(PORTNAME_BSD44_derived) && \ + !defined(PORTNAME_irix5) && !defined(PORTNAME_bsdi) && !defined(PORTNAME_aix) +extern int random(); +extern int srandom(unsigned); +#endif + + +/*------------------------------------------------------------------------- + * Check if data is Null + */ +bool +NullValue(Datum value, bool *isNull) +{ + if (*isNull) { + *isNull = false; + return(true); + } + return(false); + +} + +/*----------------------------------------------------------------------* + * check if data is not Null * + *--------------------------------------------------------------------- */ +bool +NonNullValue(Datum value, bool *isNull) +{ + if (*isNull) { + *isNull = false; + return(false); + } + return(true); + +} + +/* + * oidrand (oid o, int4 X)- + * takes in an oid and a int4 X, and will return 'true' + * about 1/X of the time. + * Useful for doing random sampling or subsetting. + * if X == 0, this will always return true; + * + * Example use: + * select * from TEMP where oidrand(TEMP.oid, 10) + * will return about 1/10 of the tuples in TEMP + * + */ +bool +oidrand(Oid o, int32 X) +{ + bool result; + + if (X == 0) return true; + + result = (random() % X == 0); + return result; +} + +/* + oidsrand(int32 X) - + seeds the random number generator + always return true +*/ +bool +oidsrand(int32 X) +{ + srand(X); + return true; +} + + + +int32 +userfntest(int i) +{ + return (i); +} |