database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-10138 Support for decimals up to 38 digits

Browse Source 
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
This commit is contained in:
Monty
2016-06-18 14:28:34 +03:00
parent e4062d4d20
commit 34eb10e406
58 changed files with 1631 additions and 1426 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
mysql-test/r/func_math.result
View File

@ -356,28 +356,28 @@ round(1.12e1, 4294967296) truncate(1.12e1, 4294967296)
11.2 11.2
select round(1.5, 2147483640), truncate(1.5, 2147483640);
round(1.5, 2147483640) truncate(1.5, 2147483640)
1.500000000000000000000000000000 1.500000000000000000000000000000
1.50000000000000000000000000000000000000 1.50000000000000000000000000000000000000
select round(1.5, -2147483649), round(1.5, 2147483648);
round(1.5, -2147483649) round(1.5, 2147483648)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select truncate(1.5, -2147483649), truncate(1.5, 2147483648);
truncate(1.5, -2147483649) truncate(1.5, 2147483648)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select round(1.5, -4294967296), round(1.5, 4294967296);
round(1.5, -4294967296) round(1.5, 4294967296)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select truncate(1.5, -4294967296), truncate(1.5, 4294967296);
truncate(1.5, -4294967296) truncate(1.5, 4294967296)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select round(1.5, -9223372036854775808), round(1.5, 9223372036854775808);
round(1.5, -9223372036854775808) round(1.5, 9223372036854775808)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select truncate(1.5, -9223372036854775808), truncate(1.5, 9223372036854775808);
truncate(1.5, -9223372036854775808) truncate(1.5, 9223372036854775808)
0 1.500000000000000000000000000000
0 1.50000000000000000000000000000000000000
select round(1.5, 18446744073709551615), truncate(1.5, 18446744073709551615);
round(1.5, 18446744073709551615) truncate(1.5, 18446744073709551615)
1.500000000000000000000000000000 1.500000000000000000000000000000
1.50000000000000000000000000000000000000 1.50000000000000000000000000000000000000
select round(18446744073709551614, -1), truncate(18446744073709551614, -1);
round(18446744073709551614, -1) truncate(18446744073709551614, -1)
18446744073709551610 18446744073709551610