Return-Path: pg_adm@postgres.berkeley.edu Received: by postgres.Berkeley.EDU (5.61/1.29) id AA07080; Tue, 13 Jul 93 02:31:43 -0700 Message-Id: <9307130931.AA07080@postgres.Berkeley.EDU> From: Wolf Guddat Subject: libpq via adt 13.6. To: postgres@postgres.berkeley.edu Sender: pg_adm@postgres.berkeley.edu To: postgres@postgres.berkeley.edu Date: Tue, 13 Jul 93 11:40:14 MESZ Cc: post-questions@postgres.berkeley.edu Mailer: Elm [revision: 70.30] Hi developers, perhaps you remember some questions which i sent to you in the last two weeks. The problem which i duscussed with you was about making postqel-queries from inside of user defined functions (in the following "userfunc"). resources: postgres4.1, ultrix4.3, decstation I try to fix what was mentioned by you and me. 1.) LIBPQ is not accessible for userfuncs -- this is somehow logic and i expected it 2.) You told me to look at a function in postgres.c named pg_eval_dest -- I've done this and i've read the code around it too Although i didn't understand all of the code (how could i) i figured out that this would be a possible but very time-expensive way (for me) to get to my final aim. I've read also the code of dest.h and it surprised me to find the following comment-line: "a local portal buffer is the destination when a backend executes a user-defined function which calls PQexec()..." Ooops! Isn't this the way i'm looking for A unix "nm .../bin/postmaster showed me that there are some functions declared similar to the ones in the libpq. (e.g. PQexec, PQparray, ...) One function is missing (PQsetdb). I tried to use this functions. 3.) I wrote a userfunc calling the PQ*-functions i found This way seems to work. I created via monitor a class I > create I (i=int4) > define function connect ..... I've done some appends like this > append I (i=2) Finally i made the following (critical call) > append I (i = connect(18)) And magically it works! (with a small warning) Everytime when i execute one of these PQ*-functions inside of connect i get the monitor message: NOTICE:Jul 13 10:10:41:PortalHeapMemoryFree: 0x101a1a90 not in alloc set! I think this has some reason in freeing the memory of my Query-String, but i was not able to avoid this message. I was totally confused about the things you wrote to me. I know i didn't used the real libpq, but is there someone (== some code) who cares about this? Knowing that it's very dangerous to program outside of the documented user- interface my fear is now that my way seems to be OK but in fact isn't. I would be very glad if you could give me some statements on this problem. PS: One more question: In the first PQexec call i submit a variable called QueryBuffer as an argument char *QueryBuffer; char *retval; QueryBuffer = (char *) palloc ( 128*sizeof(char) ); sprintf (QueryBuffer, "begin"); retval = (char *) PQexec ( (char *)QueryBuffer); If i dont cast QueryBuffer to char* my monitor says: Error: Unexpected identifier in process_portal: If i cast it it says: NOTICE:Jul 13 10:10:41:PortalHeapMemoryFree: 0x101a1a90 not in alloc set The monitor is doing this everytime i call an PQ*-function How can i turn off this Warning? ***************************************************** ** ** ** Wolf Guddat, guddat@faber.faps.uni-erlangen.de ** ** ** ***************************************************** *********************** CUT HERE FOR MY CODE: connect.c ************************** #include #include "postgres.h" #include "palloc.h" #include "builtins.h" #include "pg_lobj.h" #define EF "/user/sonst/wfguddat/XPR2PG/connect.err" extern char *PQexec (); extern PortalBuffer *PQparray (); extern int PQntuplesGroup (); extern int PQnfieldsGroup (); extern char *PQfnameGroup (); extern char *PQgetvalue (); /******************************************************************************/ /* connect erstellt: 1.7.93 geaendert: 13.7.93 Status: in action */ /******************************************************************************/ int4 *connect (arg) int4 *arg; { PortalBuffer *buffer; char *QueryBuffer; int n_groups; int n_tuples; int n_fields; int i, j, k; int t; char *retval; FILE *ef; ef = fopen (EF, "w"); fprintf (ef, "connect:\n"); fprintf (ef, "arg is [%d]\n", arg); fclose (ef); ef = fopen (EF, "a"); /* See comment on these lines in the above message */ QueryBuffer = (char *) palloc ( 128*sizeof(char) ); sprintf (QueryBuffer, "begin"); retval = (char *) PQexec ( (char *)QueryBuffer); fprintf (ef, "status for BEGIN [%s]\n", retval); sprintf (QueryBuffer, "retrieve portal eportal (I.all)"); retval = (char *) PQexec ("retrieve portal eportal (I.all)"); fprintf (ef, "status for RETRIEVE [%s]\n", retval); sprintf (QueryBuffer, "fetch all in eportal"); retval = (char *) PQexec ("fetch all in eportal"); fprintf (ef, "status for FETCH [%s]\n", retval); buffer = PQparray ("eportal"); n_groups = PQngroups (buffer); t = 0; for (k=0; k < n_groups; k++) { fprintf (ef, "new instance group number=(%d)\n", k); n_tuples = PQntuplesGroup (buffer, k); n_fields = PQnfieldsGroup (buffer, k); /* Print Att-Names */ for (i=0; i < n_fields; i++) { fprintf (ef, "%-15s", PQfnameGroup (buffer, k, i) ); } fprintf (ef, "\n"); /* Print values */ for (i=0; i< n_tuples; i++) { for (j=0; j < n_fields; j++) { fprintf (ef, "%-15s", PQgetvalue (buffer, t+i, j)); } fprintf (ef, "\n"); } t += n_tuples; } sprintf (QueryBuffer, "close eportal"); retval = PQexec ("close eportal"); fprintf (ef, "status for CLOSE EPORTAL [%s]\n", retval); sprintf (QueryBuffer, "end"); retval = PQexec ("end"); fprintf (ef, "status for END [%s]\n", retval); fclose (ef); END: return (arg); } /* connect */ ************************* these are my printfs ************************** connect: arg is [18] status for BEGIN [Enull PQexec result] status for RETRIEVE [Pbe_169888_7] status for FETCH [Peportal] new instance group number=(0) i 2 4 7 7 8 8 10 10 11 status for CLOSE EPORTAL [Enull PQexec result] status for END [Enull PQexec result]