--- In firebird-support@yahoogroups.com, "Adam" <s3057043@...> wrote:

>
> > Hi Adam
> >
> > Try this query
> > > select DISTINCT
> > > 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,

19,

> > 20,
> > < a lot snipped>
> > 230,
> > > 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242,

243,

> > 244,
> > > 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257
> > > from RDB$DATABASE;
>
> Hi Sathiesh,
>
> Yes. It looks like you are hitting an implementation limit there.
>
> A distinct must implicitly do an order by for every field, and an
> order by can have at most 255 terms in Firebird. (I know this from
> experiment not from anything I have read, but perhaps someone else

can

> show where this is documented if it is)
>
> select
> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

20,

> 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
> 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
> 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
> 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
> 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104,
> 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,

118,

> 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131,

132,

> 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145,

146,

> 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,

160,

> 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,

174,

> 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187,

188,

> 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201,

202,

> 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215,

216,

> 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,

230,

> 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243,

244,

> 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257
> from RDB$DATABASE
> order by
> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,

20,

> 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
> 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
> 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
> 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
> 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104,
> 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,

118,

> 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131,

132,

> 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145,

146,

> 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,

160,

> 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,

174,

> 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187,

188,

> 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201,

202,

> 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215,

216,

> 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,

230,

> 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243,

244,

> 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257
>
> Will also fail because of this reason, and distinct pretty much has

to

> do the same ordering.
>
> Adam
>

Hi Adam

Is there any remidy to overcome the above problem.

Thanx
Sathiesh