iterate in 10000 rows chunks over primary table

diff --git a/dbi2mongo.pl b/dbi2mongo.pl
index 369e930..2c432ad 100755 (executable)
--- a/dbi2mongo.pl
+++ b/dbi2mongo.pl
@@ -18,7 +18,7 @@ our ( $database, $collection ) = ( 'test', 'test' );
 our ( $table,  $pk ) = ( 'biblio'      => 'biblionumber' );
 our ( $table2, $fk ) = ( 'biblioitems' => 'biblionumber' );
 
-my $limit      = 50000;
+my $limit      = 10000;
 my $join_limit = 10000;
 
 require 'config.pl';
@@ -42,19 +42,38 @@ my $last_id = $last->{_id} || 0;
 
 print "import $table.$pk > $last_id from $dbi\n";
 
-my $sth = $dbh->prepare(qq{
-       select
-               $pk as _id,
-               $table.*
-       from $table
-       where $pk > ?
-       order by $pk asc
-       limit $limit
-});
+our $offset = 0;
+our $sth;
+
+sub select_table {
+
+       $sth = $dbh->prepare(qq{
+               select
+                       $pk as _id,
+                       $table.*
+               from $table
+               where $pk > ?
+               order by $pk asc
+               limit $limit
+               offset $offset
+       });
 
-$sth->execute( $last_id );
-warn "# $table columns ",dump( $sth->{NAME} );
-print "import ",$sth->rows," from $table\n";
+       print STDERR " $table:$offset ";
+       $sth->execute( $last_id );
+#      warn "# $table columns ",dump( $sth->{NAME} ) if $offset == 0;
+       print STDERR " join ", $sth->rows, " rows ";
+}
+
+our $row;
+sub fetch_row {
+       $row = $sth->fetchrow_hashref();
+       if ( ! $row && $sth->rows == $limit ) {
+               $offset += $limit;
+               select_table;
+               $row = $sth->fetchrow_hashref();
+       }
+       return $row;
+}
 
 our $join_offset = 0;
 our $sth_join;
@@ -69,14 +88,13 @@ sub join_table {
                limit $join_limit
                offset $join_offset
        });
-       print STDERR "$join_offset";
+       print STDERR " $table2:$join_offset ";
        $sth_join->execute( $last_id );
-       warn "# $table2 columns ",dump( $sth_join->{NAME} );
-       print "join ",$sth_join->rows," from $table2 offset $join_offset limit $join_limit\n";
+#      warn "# $table2 columns ",dump( $sth_join->{NAME} ) if $join_offset = 0;
+       print STDERR " join ",$sth_join->rows, " rows ";
 }
 
 our $row_join;
-
 sub fetch_row_join {
        $row_join = $sth_join->fetchrow_hashref();
        if ( ! $row_join && $sth_join->rows == $join_limit ) {
@@ -93,10 +111,11 @@ sub guess_types {
        return $row;
 }
 
+select_table;
 join_table;
 fetch_row_join;
 
-while (my $row = $sth->fetchrow_hashref() ) {
+while (my $row = fetch_row() ) {
 
        while ( $row_join && $row_join->{$fk} < $row->{$pk} ) {
                fetch_row_join;