Split up a mysqldump file with multiple databases, by database

Question

I have a mysqldump file of multiple databases (5). One of the database takes a very long time to load, is there a way to either split the mysqldump file by database, or just tell mysql to load only one of the specified databases?

Manish

Solution 1

This Perl script should do the trick.

#!/usr/bin/perl -w
#
# splitmysqldump - split mysqldump file into per-database dump files.

use strict;
use warnings;

my $dbfile;
my $dbname = q{};
my $header = q{};

while (<>) {

    # Beginning of a new database section:
    # close currently open file and start a new one
    if (m/-- Current Database\: \`([-\w]+)\`/) {
    if (defined $dbfile && tell $dbfile != -1) {
        close $dbfile or die "Could not close file!"
    } 
    $dbname = $1;
    open $dbfile, ">>", "$1_dump.sql" or die "Could not create file!";
    print $dbfile $header;
    print "Writing file $1_dump.sql ...\n";
    }

    if (defined $dbfile && tell $dbfile != -1) {
    print $dbfile $_;
    }

    # Catch dump file header in the beginning
    # to be printed to each separate dump file.  
    if (! $dbname) { $header .= $_; }
}
close $dbfile or die "Could not close file!"

Run this for the dump file containing all databases

./splitmysqldump < all_databases.sql

Solution 2

Or, it is possible to save every database into separate file directly...

#!/bin/bash
dblist=`mysql -u root -e "show databases" | sed -n '2,$ p'`
for db in $dblist; do
    mysqldump -u root $db | gzip --best > $db.sql.gz
done

Solution 3

Here is a great blog post I always re-refer to to do this kind of thing with a mysqldump.

http://gtowey.blogspot.com/2009/11/restore-single-table-from-mysqldump.html

You can easily extend it to extract individual db's.

Solution 4

I've been working on a python script which splits one big dump file into small ones, one per database. It's name is dumpsplit and here's a scratch:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sys
import re
import os

HEADER_END_MARK = '-- CHANGE MASTER TO MASTER_LOG_FILE'
FOOTER_BEGIN_MARK = '\/\*\!40103 SET TIME_ZONE=@OLD_TIME_ZONE \*\/;'
DB_BEGIN_MARK = '-- Current Database:'

class Main():
    """Whole program as a class"""

    def __init__(self,file,output_path):
        """Tries to open mysql dump file to call processment method"""
        self.output_path = output_path
        try:
            self.file_rsrc = open(file,'r')
        except IOError:
            sys.stderr.write('Can\'t open %s '+file)
        else:
            self.__extract_footer()
            self.__extract_header()
            self.__process()

    def __extract_footer(self):
        matched = False
        self.footer = ''
        self.file_rsrc.seek(0)
        line = self.file_rsrc.next()
        try:
            while line:
                if not matched:
                    if re.match(FOOTER_BEGIN_MARK,line):
                        matched = True
                        self.footer = self.footer + line
                else:
                    self.footer = self.footer + line
                line = self.file_rsrc.next()
        except StopIteration:
            pass
        self.file_rsrc.seek(0)

    def __extract_header(self):
        matched = False
        self.header = ''
        self.file_rsrc.seek(0)
        line = self.file_rsrc.next()
        try:
            while not matched:
                self.header = self.header + line
                if re.match(HEADER_END_MARK,line):
                    matched = True
                else:
                    line = self.file_rsrc.next()
        except StopIteration:
            pass
        self.header_end_pos = self.file_rsrc.tell()
        self.file_rsrc.seek(0)

    def __process(self):
        first = False
        self.file_rsrc.seek(self.header_end_pos)
        prev_line = '--\n'
        line = self.file_rsrc.next()
        end = False
        try:
            while line and not end:
                    if re.match(DB_BEGIN_MARK,line) or re.match(FOOTER_BEGIN_MARK,line):
                    if not first:
                        first = True
                    else:
                        out_file.writelines(self.footer)
                        out_file.close()
                    if not re.match(FOOTER_BEGIN_MARK,line):
                        name = line.replace('`','').split()[-1]+'.sql'
                        print name
                        out_file = open(os.path.join(self.output_path,name),'w')
                        out_file.writelines(self.header + prev_line + line)
                        prev_line = line
                        line = self.file_rsrc.next()
                    else:
                        end = True
                else:
                    if first:
                        out_file.write(line)
                    prev_line = line
                    line = self.file_rsrc.next()
        except StopIteration:
            pass

if __name__ == '__main__':
    Main(sys.argv[1],sys.argv[2])

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