v->spl_nleft=0;

right=v->spl_right;

v->spl_nright=0;

if (seed_1==0||seed_2==0 ) {

seed_1=1;

seed_2=2;

}

datum_alpha= (ArrayType*)DatumGetPointer(((GISTENTRY*)VARDATA(entryvec))[seed_1].key);

datum_l=copy_intArrayType(datum_alpha);

make clean; make; make install

2.

As it was mentioned above we don't use explicitly ID of lexems

as in OpenFTS but use hash function (crc32) instead to map lexem to

integer. Our experiments show that probability of collision is quite small:

for english text it's about 10**(-6) and 10**(-5) for russian collection.

Default installation doesn't check for collisions but if your application

does need to guarantee an exact (no collisions) search, you need

to update system table to mark index islossy:

update pg_amop set amopreqcheck = true where amopclaid =

(select oid from pg_opclass where opcname = 'gist_txtidx_ops');

If you don't bother about collisions :

update pg_amop set amopreqcheck = false where amopclaid =

(select oid from pg_opclass where opcname = 'gist_txtidx_ops');

3.

txtidx doesn't preserve words ordering (this is not critical for searching)

for performance reason, for example:

'two' 'page'

(1 row)

4.

3.

Indexed access provided by txtidx data type isn't always good

because of internal data structure we use (RD-Tree). Particularly,

queries like '!gist' will be slower than just a sequential scan,

These two queries will be processed by scanning of full index !

Very slow !

5.

4.

Following selects produce the same result

select title from titles where titleidx @@ 'patch&gist';

returnres+1-a;

}

makesign(BITVECPsign,GISTTYPE*a) {

int4k,len=ARRNELEM(a );

int4*ptr=GETARR(a );

MemSet( (void*)sign,0,sizeof(BITVEC) );

for(k=0;k<len;k++)

HASH(sign,ptr[k] );

}

gtxtidx_compress(PG_FUNCTION_ARGS) {

GISTENTRY*entry= (GISTENTRY*)PG_GETARG_POINTER(0);

*arr=crc32_sz( (uint8*)&words[ptr->pos ],ptr->len );

arr++;ptr++;

}

if (val!=toastedval )

pfree(val);

len=uniqueint(GETARR(res),val->size );

if (len!=val->size ) {

len=CALCGTSIZE(ARRKEY,len );

res= (GISTTYPE*)repalloc( (void*)res,len );

res->len=len;

}

}

if (val!=toastedval )

pfree(val);

if (res->len>TOAST_INDEX_TARGET ) {

GISTTYPE*ressign;

len=CALCGTSIZE(SIGNKEY,0 );

ressign= (GISTTYPE*)palloc(len );

ressign->len=len;

ressign->flag=SIGNKEY;

makesign(GETSIGN(ressign),res );

pfree(res);

res=ressign;

}

retval= (GISTENTRY*)palloc(sizeof(GISTENTRY));

gistentryinit(*retval,PointerGetDatum(res),

PG_RETURN_POINTER(penalty );

}

makesign(BITVECPsign,GISTTYPE*a) {

int4k,len=ARRNELEM(a );

int4*ptr=GETARR(a );

MemSet( (void*)sign,0,sizeof(BITVEC) );

for(k=0;k<len;k++)

HASH(sign,ptr[k] );

}

typedefstruct {

boolallistrue;

BITVECsign;

right=v->spl_right;

v->spl_nright=0;

if (seed_1==0||seed_2==0 ) {

seed_1=1;

seed_2=2;

}

if (cache[seed_1].allistrue ) {

datum_l= (GISTTYPE*)palloc(CALCGTSIZE(SIGNKEY|ALLISTRUE,0 ) );

and ( tq.typname='query_txt' or tq.typname='mquery_txt' );

INSERT INTO pg_amop (amopclaid, amopstrategy, amopreqcheck, amopopr)

SELECT opcl.oid, 1,false, c.opoid

SELECT opcl.oid, 1,true, c.opoid

FROM pg_opclass opcl, txtidx_ops_tmp c

WHERE

opcamid = (SELECT oid FROM pg_am WHERE amname = 'gist')

and opcname = 'gist_txtidx_ops'

and c.oprname = '@@';

INSERT INTO pg_amop (amopclaid, amopstrategy, amopreqcheck, amopopr)

SELECT opcl.oid, 2,false, c.opoid

SELECT opcl.oid, 2,true, c.opoid

FROM pg_opclass opcl, txtidx_ops_tmp c

WHERE

opcamid = (SELECT oid FROM pg_am WHERE amname = 'gist')