Remove bogus dependencies on NUMERIC_MAX_PRECISION.

NUMERIC_MAX_PRECISION is a purely arbitrary constraint on the precision
and scale you can write in a numeric typmod.  It might once have had
something to do with the allowed range of a typmod-less numeric value,
but at least since 9.1 we've allowed, and documented that we allowed,
any value that would physically fit in the numeric storage format;
which is something over 100000 decimal digits, not 1000.

Hence, get rid of numeric_in()'s use of NUMERIC_MAX_PRECISION as a limit
on the allowed range of the exponent in scientific-format input.  That was
especially silly in view of the fact that you can enter larger numbers as
long as you don't use 'e' to do it.  Just constrain the value enough to
avoid localized overflow, and let make_result be the final arbiter of what
is too large.  Likewise adjust ecpg's equivalent of this code.

Also get rid of numeric_recv()'s use of NUMERIC_MAX_PRECISION to limit the
number of base-NBASE digits it would accept.  That created a dump/restore
hazard for binary COPY without doing anything useful; the wire-format
limit on number of digits (65535) is about as tight as we would want.

In HEAD, also get rid of pg_size_bytes()'s unnecessary intimacy with what
the numeric range limit is.  That code doesn't exist in the back branches.

Per gripe from Aravind Kumar.  Back-patch to all supported branches,
since they all contain the documentation claim about allowed range of
NUMERIC (cf commit cabf5d84b).

Discussion: <2895.1471195721@sss.pgh.pa.us>

diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 0776f3bf6cf6c0b825bc80c7a437691f72e6839a..0e8a82d6f4dd5ee4bf1110ee00723a5043239f78 100644 (file)
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -759,23 +759,15 @@ pg_size_bytes(PG_FUNCTION_ARGS)
        /* Part (4): optional exponent */
        if (*endptr == 'e' || *endptr == 'E')
        {
-               long            exponent;
                char       *cp;
 
                /*
-                * Note we might one day support EB units, so if what follows isn't a
-                * number, just treat it all as a unit to be parsed.
+                * Note we might one day support EB units, so if what follows 'E'
+                * isn't a number, just treat it all as a unit to be parsed.
                 */
-               exponent = strtol(endptr + 1, &cp, 10);
+               (void) strtol(endptr + 1, &cp, 10);
                if (cp > endptr + 1)
-               {
-                       if (exponent > NUMERIC_MAX_PRECISION ||
-                               exponent < -NUMERIC_MAX_PRECISION)
-                               ereport(ERROR,
-                                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                                                errmsg("invalid size: \"%s\"", str)));
                        endptr = cp;
-               }
        }
 
        /*

diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 2fbdfe07582bd1631ebb283e1ce4e85754a94824..620226cea11d9e51f76d6f3a2f48179d7997e8f5 100644 (file)
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -753,10 +753,6 @@ numeric_recv(PG_FUNCTION_ARGS)
        init_var(&value);
 
        len = (uint16) pq_getmsgint(buf, sizeof(uint16));
-       if (len < 0 || len > NUMERIC_MAX_PRECISION + NUMERIC_MAX_RESULT_SCALE)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
-                                errmsg("invalid length in external \"numeric\" value")));
 
        alloc_var(&value, len);
 
@@ -5456,12 +5452,19 @@ set_var_from_str(const char *str, const char *cp, NumericVar *dest)
                                         errmsg("invalid input syntax for type numeric: \"%s\"",
                                                        str)));
                cp = endptr;
-               if (exponent > NUMERIC_MAX_PRECISION ||
-                       exponent < -NUMERIC_MAX_PRECISION)
+
+               /*
+                * At this point, dweight and dscale can't be more than about
+                * INT_MAX/2 due to the MaxAllocSize limit on string length, so
+                * constraining the exponent similarly should be enough to prevent
+                * integer overflow in this function.  If the value is too large to
+                * fit in storage format, make_result() will complain about it later;
+                * for consistency use the same ereport errcode/text as make_result().
+                */
+               if (exponent >= INT_MAX / 2 || exponent <= -(INT_MAX / 2))
                        ereport(ERROR,
-                                       (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-                                        errmsg("invalid input syntax for type numeric: \"%s\"",
-                                                       str)));
+                                       (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+                                        errmsg("value overflows numeric format")));
                dweight += (int) exponent;
                dscale -= (int) exponent;
                if (dscale < 0)

diff --git a/src/include/utils/numeric.h b/src/include/utils/numeric.h
index 7fd5d240c66905971870ff82d1ecfe2121750997..6c1808ec717f30e564e3830896963b9ce96053e4 100644 (file)
--- a/src/include/utils/numeric.h
+++ b/src/include/utils/numeric.h
@@ -17,8 +17,9 @@
 #include "fmgr.h"
 
 /*
- * Hardcoded precision limit - arbitrary, but must be small enough that
- * dscale values will fit in 14 bits.
+ * Limit on the precision (and hence scale) specifiable in a NUMERIC typmod.
+ * Note that the implementation limit on the length of a numeric value is
+ * much larger --- beware of what you use this for!
  */
 #define NUMERIC_MAX_PRECISION          1000
 

diff --git a/src/interfaces/ecpg/pgtypeslib/numeric.c b/src/interfaces/ecpg/pgtypeslib/numeric.c
index d061616787e970436e72ef959bd55f08e2944a6b..120794550d638063de81b75a769aa44f5c7efa4a 100644 (file)
--- a/src/interfaces/ecpg/pgtypeslib/numeric.c
+++ b/src/interfaces/ecpg/pgtypeslib/numeric.c
@@ -263,8 +263,7 @@ set_var_from_str(char *str, char **ptr, numeric *dest)
                        return -1;
                }
                (*ptr) = endptr;
-               if (exponent > NUMERIC_MAX_PRECISION ||
-                       exponent < -NUMERIC_MAX_PRECISION)
+               if (exponent >= INT_MAX / 2 || exponent <= -(INT_MAX / 2))
                {
                        errno = PGTYPES_NUM_BAD_NUMERIC;
                        return -1;

diff --git a/src/test/regress/expected/dbsize.out b/src/test/regress/expected/dbsize.out
index 20d8cb56893aac4b6dcfa471322159893e272fbe..e901a2c92a1fc6918d421d707a5ff3543dd68409 100644 (file)
--- a/src/test/regress/expected/dbsize.out
+++ b/src/test/regress/expected/dbsize.out
@@ -119,7 +119,7 @@ ERROR:  bigint out of range
 SELECT pg_size_bytes('1e100');
 ERROR:  bigint out of range
 SELECT pg_size_bytes('1e1000000000000000000');
-ERROR:  invalid size: "1e1000000000000000000"
+ERROR:  value overflows numeric format
 SELECT pg_size_bytes('1 byte');  -- the singular "byte" is not supported
 ERROR:  invalid size: "1 byte"
 DETAIL:  Invalid size unit: "byte".