com.sleepycat.je.util

Class DbDump

java.lang.Object

com.sleepycat.je.util.DbDump

Direct Known Subclasses:

DbScavenger

public class DbDump
extends java.lang.Object

Dump the contents of a database. This utility may be used programmatically or from the command line.

When using this utility as a command line program, and the application uses custom key comparators, be sure to add the jars or classes to the classpath that contain the application's comparator classes.

 java { com.sleepycat.je.util.DbDump |
        -jar je-<version>.jar DbDump }
   -h <dir>           # environment home directory
  [-f <fileName>]     # output file, for non -rR dumps
  [-l]                # list databases in the environment
  [-p]                # output printable characters
  [-r]                # salvage mode
  [-R]                # aggressive salvage mode
  [-d] <directory>    # directory for *.dump files (salvage mode)
  [-s <databaseName>] # database to dump
  [-v]                # verbose in salvage mode
  [-V]                # print JE version number

See main(java.lang.String[]) for a full description of the command line arguments.

To dump a database to a stream from code:

    DbDump dump = new DbDump(env, databaseName, outputStream, boolean);
    dump.dump();
 

Because a DATA=END marker is used to terminate the dump of each database, multiple databases can be dumped and loaded using a single stream. The dump() method leaves the stream positioned after the last line written and the DbLoad.load() method leaves the stream positioned after the last line read.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	dbName
protected boolean	doAggressiveScavengerRun
protected boolean	doScavengerRun
protected Environment	env
protected java.io.File	envHome
protected boolean	formatUsingPrintable
protected java.lang.String	outputDirectory
protected java.io.PrintStream	outputFile
protected boolean	verbose

Constructor Summary

Constructors

Constructor and Description
DbDump(Environment env, java.lang.String dbName, java.io.PrintStream outputFile, boolean formatUsingPrintable) Create a DbDump object for a specific environment and database.
DbDump(Environment env, java.lang.String dbName, java.io.PrintStream outputFile, java.lang.String outputDirectory, boolean formatUsingPrintable) Deprecated. Please use the 4-arg ctor without outputDirectory instead.

Method Summary

Modifier and Type	Method and Description
void	dump() Perform the dump.
protected void	dumpOne(java.io.PrintStream o, byte[] ba, boolean formatUsingPrintable)
static void	main(java.lang.String[] argv) The main used by the DbDump utility.
protected void	openEnv(boolean doRecovery)
protected boolean	parseArgs(java.lang.String[] argv)
protected void	printHeader(java.io.PrintStream o, boolean dupSort, boolean formatUsingPrintable)
protected void	printUsage(java.lang.String msg)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

envHome

protected java.io.File envHome

env

protected Environment env

dbName

protected java.lang.String dbName

formatUsingPrintable

protected boolean formatUsingPrintable

outputDirectory

protected java.lang.String outputDirectory

outputFile

protected java.io.PrintStream outputFile

doScavengerRun

protected boolean doScavengerRun

doAggressiveScavengerRun

protected boolean doAggressiveScavengerRun

verbose

protected boolean verbose

Constructor Detail

DbDump

@Deprecated
public DbDump(Environment env,
                          java.lang.String dbName,
                          java.io.PrintStream outputFile,
                          java.lang.String outputDirectory,
                          boolean formatUsingPrintable)

Deprecated. Please use the 4-arg ctor without outputDirectory instead.

DbDump

public DbDump(Environment env,
              java.lang.String dbName,
              java.io.PrintStream outputFile,
              boolean formatUsingPrintable)

Create a DbDump object for a specific environment and database.

Parameters:

env - The Environment containing the database to dump.

dbName - The name of the database to dump.

outputFile - The output stream to dump the database to.

formatUsingPrintable - true if the dump should use printable characters.

Method Detail

main

public static void main(java.lang.String[] argv)
                 throws java.lang.Exception

The main used by the DbDump utility.

Parameters:

argv - The arguments accepted by the DbDump utility.

 usage: java { com.sleepycat.je.util.DbDump | -jar
 je-<version>.jar DbDump }
             [-f output-file] [-l] [-p] [-V]
             [-s database] -h dbEnvHome [-rR] [-v]
             [-d directory]
 

-f - the file to dump to. If omitted, output is to System.out. Does not apply when -r or -R is used.

-l - list the databases in the environment.

-p - output printable characters.

If characters in either the key or data items are printing characters (as defined by isprint(3)), use printing characters in file to represent them. This option permits users to use standard text editors and tools to modify the contents of databases.

-V - display the version of the JE library.

-s database - the database to dump. Does not apply when -r or -R is used.

-h dbEnvHome - the directory containing the database environment.

-d directory - the output directory for *.dump files. Applies only when -r or -R is used.

-v - print progress information to stdout for -r or -R mode.

-r - Salvage data from possibly corrupt data files.

The records for all databases are output. The records for each database are saved into <databaseName>.dump files in the current directory.

This option recreates the Btree structure in memory, so as large a heap size as possible should be specified. If -r cannot be used due to insufficient memory, use -R instead.

When used on uncorrupted data files, this option should return equivalent data to a normal dump, but most likely in a different order; in other words, it should output a transactionally correct data set. However, there is one exception where not all committed records will be output:

• When a committed transaction spans more than one .jdb file, and the last file in this set of files has been deleted by the log cleaner but earlier files have not, records for that transaction that appear in the earlier files will not be output. This is because the Commit entry in the last file is missing, and DbDump believes that the transaction was not committed. Such missing output should be relatively rare. Note that records in deleted files will be output, because they were migrated forward by the log cleaner and are no longer associated with a transaction.

-R - Aggressively salvage data from a possibly corrupt file.

The records for all databases are output. The records for each database are saved into <databaseName>.dump files in the current directory.

Unlike -r, the -R option does not recreate the Btree structure in memory. However, it does use a bit set to track all committed transactions, so as large a heap size as possible should be specified.

-R also differs from -r in that -R does not return a transactionally correct data set. This is because the Btree information is not reconstructed in memory. Therefore, data dumped in this fashion will almost certainly have to be edited by hand or other means before or after the data is reloaded. Be aware of the following abnormalities.

• Deleted records are often output. An application specific technique should normally be used to correct for this.
• Multiple versions of the same record are sometimes output. When this happens, the more recent version of a record is output first. Therefore, the -n option should normally be used when running DbLoad.
• When a committed transaction spans more than one .jdb file, and the last file in this set of files has been deleted by the log cleaner but earlier files have not, records for that transaction that appear in the earlier files will not be output. This is because the Commit entry in the last file is missing, and DbDump believes that the transaction was not committed. Such missing output should be relatively rare. Note that records in deleted files will be output, because they were migrated forward by the log cleaner and are no longer associated with a transaction. (This abnormality also occurs with -r.)

Throws:

EnvironmentFailureException - if an unexpected, internal or environment-wide failure occurs.

java.lang.Exception

printUsage

protected void printUsage(java.lang.String msg)

parseArgs

protected boolean parseArgs(java.lang.String[] argv)
                     throws java.io.IOException

Throws:

java.io.IOException

openEnv

protected void openEnv(boolean doRecovery)
                throws EnvironmentNotFoundException,
                       EnvironmentLockedException

Throws:

EnvironmentNotFoundException

EnvironmentLockedException

dump

public void dump()
          throws EnvironmentNotFoundException,
                 EnvironmentLockedException,
                 DatabaseNotFoundException,
                 java.io.IOException

Perform the dump.

Throws:

EnvironmentFailureException - if an unexpected, internal or environment-wide failure occurs.

java.io.IOException - in subclasses.

EnvironmentNotFoundException

EnvironmentLockedException

DatabaseNotFoundException

printHeader

protected void printHeader(java.io.PrintStream o,
                           boolean dupSort,
                           boolean formatUsingPrintable)

dumpOne

protected void dumpOne(java.io.PrintStream o,
                       byte[] ba,
                       boolean formatUsingPrintable)