Return-Path: pg_adm@postgres.berkeley.edu Received: by postgres.Berkeley.EDU (5.61/1.29) id AA22258; Fri, 11 Sep 92 07:37:06 -0700 Message-Id: <9209111437.AA22258@postgres.Berkeley.EDU> From: "Schenkelaars.V.F" Subject: R-tree bug, patches included. To: postgres@postgres.berkeley.edu Sender: pg_adm@postgres.berkeley.edu To: postgres@postgres.berkeley.edu (Postgres mailing list) Date: Fri, 11 Sep 92 16:37:36 MET DST Cc: mao@postgres.berkeley.edu (Mike Olson), bug-postgres@postgres.berkeley.edu (Postgres Bugreport) X-Mailer: ELM [version 2.3 PL11] Dear Postgres Group, During my attempt to add a new access method to Postgres, I encountered a strange decision of the R-tree implementor. The rt_box_size function does return a int type. This is very strange since the box coordinates are doubles. The return type can never have the required accuracy. In my opinion this function should at least return a float. I`m aware that floats are returned by reference rather than by value. Since my access method "The Reactive-tree" is quite similar to the R-tree I needed the size function in the same way. I have changed the int type into a float pointer type. This change has to be done in two functions. I have made these changes and tested them. It works ok on a sparc station. Below are the patches for fixing this bug. Mike, I`ve almost finished the Reactive-tree. I'll let you know when it is "bullet-proof". I`m intending to write a "How to add a new access method to Postgres" manual. Since it seems that there are more people strugling with this material, and since it looks as if I am the only one outside the Postgres group who has (almost) managed to add a new access method, It seems a good idea to me to share my experience with other users. Of course this manual shall be available for all Postgres users. The same counts for the Reactive-tree code. Greetings, ____________________ \ / . _ _ _ _ | \/ ( ( \ (_ (-' ( \ | P.S. Postgres has proven to be open, although one will need a good guide to explore some of it's mazes. -------------------------------------------------------------------------------- Vincent F. Schenkelaars | Company: FEL-TNO | Private: Email : V.F.Schenkelaars@tnofel.fel.tno.nl | address: Oude Waalsdorperweg 63 | Groenhovenstraat 12 Postbus 96864 | 2509 JG Den Haag | 2311 BT Leiden The Netherlands | The Netherlands Phone : Holland 070-3264221 | Holland 071-125576 Fax : Holland 070-3280961 | -------------------------------------------------------------------------------- rtree.c patch ---------- CUT HERE ------------------------- *** rtree.c Fri Sep 11 14:57:11 1992 --- rtree.c.fixed Fri Sep 11 15:16:44 1992 *************** *** 313,319 **** { char *oldud; Page p; ! int old_size, newd_size; RegProcedure union_proc, size_proc; Buffer b; --- 313,319 ---- { char *oldud; Page p; ! float *old_size, *newd_size; RegProcedure union_proc, size_proc; Buffer b; *************** *** 329,341 **** oldud = (char *) PageGetItem(p, PageGetItemId(p, stk->rts_child)); oldud += sizeof(IndexTupleData); ! old_size = (int) fmgr(size_proc, oldud); datum = (char *) fmgr(union_proc, oldud, datum); ! newd_size = (int) fmgr(size_proc, datum); /* XXX assume constant-size data items here */ ! if (newd_size != old_size) { bcopy(datum, oldud, att_size); WriteBuffer(b); rttighten(r, stk->rts_parent, datum, att_size); --- 329,341 ---- oldud = (char *) PageGetItem(p, PageGetItemId(p, stk->rts_child)); oldud += sizeof(IndexTupleData); ! old_size = (float *) fmgr(size_proc, oldud); datum = (char *) fmgr(union_proc, oldud, datum); ! newd_size = (float *) fmgr(size_proc, datum); /* XXX assume constant-size data items here */ ! if (*newd_size != *old_size) { bcopy(datum, oldud, att_size); WriteBuffer(b); rttighten(r, stk->rts_parent, datum, att_size); *************** *** 740,753 **** int i; char *ud, *id; char *datum; ! int isize, usize, dsize; ! int which, which_grow; RegProcedure union_proc, size_proc; union_proc = index_getprocid(r, 1, RT_UNION_PROC); size_proc = index_getprocid(r, 1, RT_SIZE_PROC); id = ((char *) it) + sizeof(IndexTupleData); ! isize = (int) fmgr(size_proc, id); maxoff = PageGetMaxOffsetIndex(p); which_grow = -1; which = -1; --- 740,753 ---- int i; char *ud, *id; char *datum; ! float *isize, *usize, *dsize, which_grow; ! int which; RegProcedure union_proc, size_proc; union_proc = index_getprocid(r, 1, RT_UNION_PROC); size_proc = index_getprocid(r, 1, RT_SIZE_PROC); id = ((char *) it) + sizeof(IndexTupleData); ! isize = (float *) fmgr(size_proc, id); maxoff = PageGetMaxOffsetIndex(p); which_grow = -1; which = -1; *************** *** 755,771 **** for (i = 0; i <= maxoff; i++) { datum = (char *) PageGetItem(p, PageGetItemId(p, i)); datum += sizeof(IndexTupleData); ! dsize = (int) fmgr(size_proc, datum); ud = (char *) fmgr(union_proc, datum, id); ! usize = (int) fmgr(size_proc, ud); pfree(ud); ! if (which_grow < 0 || usize - dsize < which_grow) { which = i; ! which_grow = usize - dsize; if (which_grow == 0) break; } } return (which); } --- 755,774 ---- for (i = 0; i <= maxoff; i++) { datum = (char *) PageGetItem(p, PageGetItemId(p, i)); datum += sizeof(IndexTupleData); ! dsize = (float *) fmgr(size_proc, datum); ud = (char *) fmgr(union_proc, datum, id); ! usize = (float *) fmgr(size_proc, ud); pfree(ud); ! if (which_grow < 0 || *usize - *dsize < which_grow) { which = i; ! which_grow = *usize - *dsize; if (which_grow == 0) break; } } + pfree(dsize); + pfree(usize); + pfree(isize); return (which); } ---------- CUT HERE ------------------------- rtproc.c patch ---------- CUT HERE ------------------------- ------------------------------------------------------------- *** rtproc.c Fri Sep 11 15:18:36 1992 --- rtproc.c.fixed Fri Sep 11 15:24:28 1992 *************** *** 52,67 **** return (n); } ! int rt_box_size(a) BOX *a; { ! int size; if (a == (BOX *) NULL || a->xh <= a->xl || a->yh <= a->yl) return (0); ! size = (int) (fabs(a->xh - a->xl) * fabs(a->yh - a->yl)); return (size); } --- 52,68 ---- return (n); } ! float * rt_box_size(a) BOX *a; { ! float *size; + size = (float *) palloc (sizeof(float)); if (a == (BOX *) NULL || a->xh <= a->xl || a->yh <= a->yl) return (0); ! *size = (float) (fabs(a->xh - a->xl) * fabs(a->yh - a->yl)); return (size); } ---------- CUT HERE -------------------------