mariadb/libmysqld
Monty 34eb10e406 MDEV-10138 Support for decimals up to 38 digits
Decimals with float, double and decimal now works the following way:

- DECIMAL_NOT_SPECIFIED is used when declaring DECIMALS without a firm number
  of decimals.  It's only used in asserts and my_decimal_int_part.
- FLOATING_POINT_DECIMALS (31) is used to mark that a FLOAT or DOUBLE
  was defined without decimals. This is regarded as a floating point value.
- Max decimals allowed for FLOAT and DOUBLE is FLOATING_POINT_DECIMALS-1
- Clients assumes that float and double with decimals >= NOT_FIXED_DEC are
  floating point values (no decimals)
- In the .frm decimals=FLOATING_POINT_DECIMALS are used to define
  floating point for float and double (31, like before)

To ensure compatibility with old clients we do:

- When storing float and double, we change NOT_FIXED_DEC to
  FLOATING_POINT_DECIMALS.
- When creating fields from .frm we change for float and double
  FLOATING_POINT_DEC to NOT_FIXED_DEC
- When sending definition for a float/decimal field without decimals
  to the client as part of a result set we convert NOT_FIXED_DEC to
  FLOATING_POINT_DECIMALS.
- variance() and std() has changed to limit the decimals to
  FLOATING_POINT_DECIMALS -1 to not get the double converted floating point.
  (This was to preserve compatiblity)
- FLOAT and DOUBLE still have 30 as max number of decimals.

Bugs fixed:

variance() printed more decimals than we support for double values.

New behaviour:
- Strings now have 38 decimals instead of 30 when converted to decimal
- CREATE ... SELECT with a decimal with > 30 decimals will create a column
  with a smaller range than before as we are trying to preserve the number of
  decimals.


Other changes
- We are now using the obsolete bit FIELDFLAG_LEFT_FULLSCREEN to specify
  decimals > 31
- NOT_FIXED_DEC is now declared in one place
- For clients, NOT_FIXED_DEC is always 31 (to ensure compatibility).
  On the server NOT_FIXED_DEC is DECIMAL_NOT_SPECIFIED (39)
- AUTO_SEC_PART_DIGITS is taken from DECIMAL_NOT_SPECIFIED
- DOUBLE conversion functions are now using DECIMAL_NOT_SPECIFIED instead of
  NOT_FIXED_DEC
2016-06-22 22:04:55 +03:00
..
examples Bug#17633291: SET PROPER COMPILE OPTIONS FOR CLANG 2014-10-13 09:52:28 +02:00
CMakeLists.txt MDEV-5535: Cannot reopen temporary table 2016-06-10 18:39:43 -04:00
emb_qcache.cc MDEV-5120 Test suite test maria-no-logging fails 2014-09-30 20:31:14 +03:00
emb_qcache.h Updated/added copyright headers 2011-06-30 17:46:53 +02:00
embedded_priv.h Updated/added copyright headers 2011-06-30 17:46:53 +02:00
lib_sql.cc MDEV-10138 Support for decimals up to 38 digits 2016-06-22 22:04:55 +03:00
libmysqld.c Merge with MariaDB 5.1 2011-11-24 18:48:58 +02:00
libmysqld.def merge with 5.3 2011-10-19 21:45:18 +02:00
libmysqld.rc query_id and my_xid -> ulonglong 2005-01-27 22:38:56 +01:00
resource.h query_id and my_xid -> ulonglong 2005-01-27 22:38:56 +01:00