doc: update NUMERIC to state that only some ops are exact

Report by Tom Lane
This commit is contained in:
Bruce Momjian 2015-03-24 19:57:52 -04:00
parent 1d8198bb44
commit 278edd9ed3

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@ -498,11 +498,13 @@
<para>
The type <type>numeric</type> can store numbers with a
very large number of digits and perform calculations exactly. It is
especially recommended for storing monetary amounts and other
quantities where exactness is required. However, arithmetic on
<type>numeric</type> values is very slow compared to the integer
types, or to the floating-point types described in the next section.
very large number of digits. It is especially recommended for
storing monetary amounts and other quantities where exactness is
required. Calculations with <type>numeric</type> values yield exact
results where possible, e.g. addition, subtraction, multiplication.
However, calculations on <type>numeric</type> values are very slow
compared to the integer types, or to the floating-point types
described in the next section.
</para>
<para>