Optimization in C

From: Jerome Raupach <jraupach(at)intelcom(dot)fr>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Optimization in C
Date: 2000-08-17 15:26:19
Message-ID: 399C041B.85D480ED@intelcom.fr
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This solution isn't good when there are +10000 tuples in the table, it's
slowly...
anybody can help me ? :

string = "SELECT service, noeud, rubrique FROM table" ;
res = PQexec( conn, string.data() ) ;
if ( (! res) || (status = PQresultStatus( res ) !=
PGRES_TUPLES_OK) )
{
cerr << _ERROR << "Problem SELECT ! " << endl ;
cerr << _ERROR << "Error : " << PQresStatus( status ) <<
endl ;
cerr << _ERROR << "Error : " << PQresultErrorMessage(
res ) << endl ;
PQclear( res ) ;
}
else
{
for (int m=0; m < PQntuples( res ); m++)
{
service = PQgetvalue( resultat1, m, 0 ) ;
noeud = PQgetvalue( resultat1, m, 1 ) ;
rubrique = PQgetvalue( resultat1, m, 2 ) ;

commande = "SELECT SUM(date) FROM table WHERE
service='" + service +
"' AND noeud='" + noeud + "' AND rubrique='"+ rubrique + "'" ;
res1 = PQexec( conn, string.data() ) ;
if ( (! res1) || (status = PQresultStatus( res1
) != PGRES_TUPLES_OK)
)
{
cerr << _ERROR << "Problem SUM ! " <<
endl ;
cerr << _ERROR << "Error : " <<
PQresStatus( status ) << endl ;
cerr << _ERROR << "Error : " <<
PQresultErrorMessage( res1 ) << endl
;
PQclear( res1 ) ;
}
else
{
cout << _TRACE << "SUM ok." << endl ;
PQclear( res1 ) ;
}
}
PQclear( res ) ;
}

Thanks. jerome.

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