The BDB XML shell has a built in help facility, simply type
help at the command line:
The text displayed by the
help command changes
frequently, and so what you see in your version
of the BDB XML shell may differ from what is
shown below.
dbxml> help
Command Summary
---------------
# - Comment. Does nothing
abort - Aborts the current transaction
addAlias - Add an alias to the default container
addIndex - Add an index to the default container
commit - Commits the current transaction, and starts a new one
compactContainer - Compact a container to shrink it's size
contextQuery - Execute query expression using the last results as
the context item
cquery - Execute an expression in the context of the default
container
createContainer - Creates a new container, which becomes the default
container
debug - Debug the given query expression, or the default
pre-parsed query
debugOptimization - Debug optimization command -- internal use only
delIndex - Delete an index from the default container
echo - Echo to output
getDocuments - Gets document(s) by name from default container
getMetaData - Get a metadata item from the named document
help - Print help information. Use 'help commandName' for
extended help
info - Get info on default container
listIndexes - List all indexes in the default container
lookupEdgeIndex - Performs an edge index lookup in the default container
lookupIndex - Performs an index lookup in the default container
lookupStats - Look up index statistics on the default container
openContainer - Opens a container, and uses it as the default
container
preload - Pre-loads (opens) a container
prepare - Prepare the given query expression as the default
pre-parsed query
print - Prints most recent results, optionally to a file
putDocument - Insert a document into the default container
query - Execute the given query expression, or the default
pre-parsed query
queryPlan - Prints the query plan for the specified query
expression
quit - Exit the program
reindexContainer - Reindex a container, optionally changing index type
removeAlias - Remove an alias from the default container
removeContainer - Removes a container
removeDocument - Remove a document from the default container
run - Runs the given file as a script
setAutoIndexing - Set auto-indexing state of the default container
setBaseUri - Set/get the base uri in the default context
setIgnore - Tell the shell to ignore script errors
setLazy - Sets lazy evaluation on or off in the default context
setMetaData - Set a metadata item on the named document
setNamespace - Create a prefix->namespace binding in the default
context
setProjection - Enables or disables the use of the document
projection optimization
setQueryTimeout - Set a query timeout in seconds in the default context
setReturnType - Sets the return type on the default context
setTypedVariable - Set a variable to the specified type in the default
context
setVariable - Set a variable in the default context
setVerbose - Set the verbosity of this shell
sync - Sync current container to disk
time - Wrap a command in a wall-clock timer
transaction - Create a transaction for all subsequent operations
to use
upgradeContainer - Upgrade a container to the current container format
Any given command has additional detailed help. For example:
dbxml> help createContainer
createContainer -- Creates a new container, which becomes the default
container
Usage: createContainer <containerName> [n|in|d|id] [[no]validate]
Creates a new default container; the old default is closed.
The default is to create a node storage container, with node indexes.
A second argument of "d" creates a Wholedoc storage container, and
"id" creates a document storage container with node indexes.
A second argument of "n" creates a node storage container, and
"in" creates a node storage container with node indexes.
The optional third argument indicates whether or not to validate
documents on insertion
A containerName of "" creates an in-memory container.
This command uses the XmlManager::createContainer() method.
The help text has valuable information about the command and the API calls that are used to implement a particular command. This helps you to find the relevant section of the API documentation where more detail is available and also serves as a way to explore a commonly used subset of the API calls in an interactive fashion.
The debug command provides a
debugging facility for XQueries. However, it is
currently only useful for developers with a deep
understanding of query plans. That said, you can try
out the debugger by typing:
debug xquery
where xquery is the query that you want to debug. (XQueries are described in the next chapter of this manual).
Once in the debugger, you can get debugger-specific help by using the
help command. Use the step command to step
forward one instruction in the query plan. Use run to
execute the remainder of the query plan.