Q: Bigdump stops on extended inserts. Help!

A: Bigdump isn’t able to handle dump files with extended inserts. It’s a limitation on how Bigdump splits the files and probably won’t be resolved in the future. Please turn off extended inserts when exporting database from phpMyAdmin. If you only have a dump file with extended inserts please ask for our support service in order to convert it into a file usable by BigDump.

Q: How can I export a database from phpMyAdmin without extended inserts?

A: In the older versions of phpMyAdmin look for extended inserts switch in the export settings and set it to off. In the newer phpMyAdmin versions select Include column names in every INSERT statement for Syntax to use in the Data dump options of the export dialog.

Q: The import process is very slow. What happens?

A: The speed of the dump import process is mostly depending on the mySQL server performance. The same dump file can take few minutes or few hours to import depending on mySQL performance of the particular system. Bigdump can’t make the import process faster or slower. It just gives your dump file query by query to the mySQL server.

Q: I get an error: “MySQL: Bad syntax near DEFAULT CHARACTER SET…”. Why?

A: You are probably trying to restore a dump file from a newer mySQL database version into an older mySQL database. Sorry, this is obviously not a very good idea and this can’t work. You have to recreate the dump file in compatibility mode or remove all incompatible stuff by hand.

Q: I get an error: “MySQL: Table ‘some_tbl_name’ already exists”. Why?

A: Your dump file doesn’t contain DROP queries. Use phpMyAdmin to drop all the tables on the target database which must be restored before you start the import.

Q: I get an error: “MySQL: Variable ‘xyz’ can’t be set to the value of ‘NULL'”. Why?

A: Your dump file probably contains a statement like this: SET character_set_client = @saved_cs_client; Bigdump is not able to restore settings saved at the beginning of the import process. However you can skip this error message by adding a comment setting $comment[]='SET character_set_client = @saved_cs_client;'; to the BigDump configuration.

Q: I get an error: “MySQL: Duplicate entry ‘X’ for key Y”. Why?

A: There is something broken in your dump file as it tries to create duplicated entries where a unique key is defined by CREATE TABLE statement. In some cases it can still work if you ignore all these errors. In order to do so you have to replace all INSERT INTO by INSERT IGNORE INTO in your dumpfile using a text editor.

Q: I get PHP errors “Value to large” when trying to import a file larger than 2 GB. Why?

A: Some PHP versions are broken and can’t handle files largen than 2 GB. Ask your hoster to apply this PHP patch for solution.

Q: I get an error: “Fatal error: Allowed memory size of xxx bytes exhausted” or “MySQL server has gone away”. Why?

A: Your dump file probably contains extended inserts. An extended insert contains all table entries within one SQL query. BigDump isn’t able to split such SQL queries. Please turn off extended inserts when exporting database from phpMyAdmin. If you only have a dump file with extended inserts please ask for our support service in order to convert it into a file usable by BigDump.

Q: Why does BigDump fail putting strange SQL errors if I run it on MS Windows based server?

A: This is IMHO a bug in the PHP4 and PHP5 that is crashing BigDump on Win32 if using a dump file with DOS encoded line breaks (contact me for details). As workaround create your dump with only the UNIX line breaks or convert it into UNIX format using some text editor. Then you will be able to run BigDump also on Win32.

Q: I get an error: “PHP version 4.1.0 is required for BigDump to proceed. You have PHP 4.3.x installed. Sorry!”. Why?

A: This is strange but it happens. Something is wrong with you PHP installation. As workaround you can remove from bigdump.php five code lines following on the comment // Check PHP version. This will skip the version check.

Q: Can I use dump files created by other software than phpMyAdmin?

A: You can use any text dump file at your own risk. Although it’s very important for BigDump to find a semicolon followed by a line break at the end of each query. It won’t work else since it has no time to parse the queries to find their proper ends. Further BigDump behaviour can be unpredictable if your dump file is using double quotes to surround strings. BigDump won’t work too if your dump file contains any proprietary comment lines (like in some dumps created by other tools). Although you can use the $comment setting in bigdump.php to drop non-standard comment lines by their first characters. Apart from that BigDump doesn’t filter the dump file in any way.

Q: Do you plan to add a feature for creating/exporting large mySQL dumps?

A: Actually no. Creating large dump files usually works well even with phpMyAdmin or other web tools. If your database is too large for that you should think about other hosting solution which allows shell access.

Q: Why don’t you provide any facility to input the database configuration from the browser form?

A: Input the database configuration from the form would be very insecure since the settings must be saved in the cookies or returned to your browser everytime the session ends.