memory leak while trying to update/alter column in postgresql - Mailing list pgsql-general

I am trying to update/alter two columns-comment and id in a table called xxx using postgresql. Though the compiler does not show any errors but Valgrind gives major memory leak errors. The code is:

int main()

{

PGconn *conn;

       PGresult *res;

int i=0,nFields=0,row=0,col=0;

conn = PQconnectdb("dbname=test1 host=localhost user=postgres password=yyy");

   if(PQstatus(conn) == CONNECTION_BAD) 

   {

fprintf(stderr, "Connection to database \"%s\" failed.\n", PQerrorMessage(conn));

fprintf(stderr, "%s", PQerrorMessage(conn));

exit_nicely(conn);

}

   

res = PQexec(conn, "IF COL_LENGTH('xxx','comment') IS NULL");

if(res)

res = PQexec(conn, "ALTER TABLE xxx ADD comment VARCHAR(500)");

   else

res = PQexec(conn, "UPDATE TABLE xxx ADD comment VARCHAR(500)");

res = PQexec(conn, "IF COL_LENGTH('xxx','id') IS NULL");

if(res)

res = PQexec(conn, "ALTER TABLE xxx ADD id VARCHAR(50)");

   else

res = PQexec(conn, "UPDATE TABLE xxx ADD id VARCHAR(50)");

  res = PQexec(conn, "SELECT * FROM xxx");

if((!res) || (PQresultStatus(res) != PGRES_TUPLES_OK))

{

fprintf(stderr, "SELECT command did not return tuples properly\n");

PQclear(res);

}

PQclear(res);

PQfinish(conn);

return 0;

}

Valgrind gives the following errors:

$ valgrind --track-origins=yes --leak-check=full ./Gwidd_uniprot_map2 xaa

==4525== Memcheck, a memory error detector

==4525== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.

==4525== Using Valgrind-3.6.1 and LibVEX; rerun with -h for copyright info

==4525== Command: ./Gwidd_uniprot_map2 xaa

==4525== 

--4525-- ./Gwidd_uniprot_map2:

--4525-- dSYM directory has wrong UUID; consider using --dsymutil=yes

==4525== 

==4525== HEAP SUMMARY:

==4525==     in use at exit: 262,994 bytes in 751 blocks

==4525==   total heap usage: 1,012 allocs, 261 frees, 345,158 bytes allocated

==4525== 

==4525== 2,248 (200 direct, 2,048 indirect) bytes in 1 blocks are definitely lost in loss record 400 of 414

==4525==    at 0x100011345: malloc (vg_replace_malloc.c:236)

==4525==    by 0x10007B7E0: PQmakeEmptyPGresult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008DF30: pqGetErrorNotice3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008CC00: pqParseInput3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007ECD9: parseInput (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007EE3F: PQgetResult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F6F1: PQexecFinish (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F1DC: PQexec (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10000199A: main (in ./Gwidd_uniprot_map2)

==4525== 

==4525== 2,248 (200 direct, 2,048 indirect) bytes in 1 blocks are definitely lost in loss record 401 of 414

==4525==    at 0x100011345: malloc (vg_replace_malloc.c:236)

==4525==    by 0x10007B7E0: PQmakeEmptyPGresult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008DF30: pqGetErrorNotice3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008CC00: pqParseInput3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007ECD9: parseInput (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007EE3F: PQgetResult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F6F1: PQexecFinish (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F1DC: PQexec (in /usr/lib/libpq.5.dylib)

==4525==    by 0x1000019B5: main (in ./Gwidd_uniprot_map2)

==4525== 

==4525== 2,248 (200 direct, 2,048 indirect) bytes in 1 blocks are definitely lost in loss record 402 of 414

==4525==    at 0x100011345: malloc (vg_replace_malloc.c:236)

==4525==    by 0x10007B7E0: PQmakeEmptyPGresult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008DF30: pqGetErrorNotice3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008CC00: pqParseInput3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007ECD9: parseInput (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007EE3F: PQgetResult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F6F1: PQexecFinish (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F1DC: PQexec (in /usr/lib/libpq.5.dylib)

==4525==    by 0x1000019DF: main (in ./Gwidd_uniprot_map2)

==4525== 

==4525== 2,248 (200 direct, 2,048 indirect) bytes in 1 blocks are definitely lost in loss record 403 of 414

==4525==    at 0x100011345: malloc (vg_replace_malloc.c:236)

==4525==    by 0x10007B7E0: PQmakeEmptyPGresult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008DF30: pqGetErrorNotice3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10008CC00: pqParseInput3 (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007ECD9: parseInput (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007EE3F: PQgetResult (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F6F1: PQexecFinish (in /usr/lib/libpq.5.dylib)

==4525==    by 0x10007F1DC: PQexec (in /usr/lib/libpq.5.dylib)

==4525==    by 0x1000019FA: main (in ./Gwidd_uniprot_map2)

==4525== 

==4525== LEAK SUMMARY:

==4525==    definitely lost: 800 bytes in 4 blocks

==4525==    indirectly lost: 8,192 bytes in 4 blocks

==4525==      possibly lost: 0 bytes in 0 blocks

==4525==    still reachable: 254,002 bytes in 743 blocks

==4525==         suppressed: 0 bytes in 0 blocks

==4525== Reachable blocks (those to which a pointer was found) are not shown.

==4525== To see them, rerun with: --leak-check=full --show-reachable=yes

==4525== 

==4525== For counts of detected and suppressed errors, rerun with: -v

==4525== ERROR SUMMARY: 4 errors from 4 contexts (suppressed: 0 from 0)

Please provide suggestions to solve the problem.

Thanks!