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The [[Options#ADDCACHEIf {{Option|ADDCACHE]] option will first cache }} is enabled, the input will be cached before adding it is added to the database. This is helpful when the input documents to be added are expected to eat up consume too much main memory.
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You can access multiple databases in a single query:
<pre classsyntaxhighlight lang="brush:xquery">
for $i in 1 to 100
return db:open('books' || $i)//book/title
</presyntaxhighlight>
If the [[Options#DEFAULTDB{{Option|DEFAULTDB]] }} option is turned on, the path argument of the {{Code|fn:doc}} or {{Code|fn:collection}} function will first be resolved against the globally opened database.
Two more functions are available for retrieving information on database nodes:
The {{Code|fn:document-uri}} and {{Code|fn:base-uri}} functions return URIs that can also be reused as arguments for the {{Code|fn:doc}} and {{Code|fn:collection}} functions. As a result, the following example query always returns {{Code|true}}:
<pre classsyntaxhighlight lang="brush:xquery">
every $c in collection('anyDB')
satisfies doc-available(document-uri($c))
</presyntaxhighlight>
If the argument of {{Code|fn:doc}} or {{Code|fn:collection}} does not start with a valid database name, or if the addressed database does not exist, the string is interpreted as URI reference, and the documents found at this location will be returned. Examples:
* {{Code|doc("http://web.de")}}: retrieves the addressed URI and returns it as a main-memory document node.
* {{Code|doc("myfile.xml")}}: retrieves the given file from the file system and returns it as a main-memory document node. Note that updates to main-memory nodes are not automatically written back to disk unless the <code>[[Options#WRITEBACK{{Option|WRITEBACK]]</code> }} option is set.
* {{Code|collection("/path/to/docs")}}: returns a main-memory collection with all XML documents found at the addressed file path.
If the API you use does not support binary output (this is e.g. the case for various [[Clients|Client]] language bindings), you need to convert your binary data to its string representation before returning it to the client:
<pre classsyntaxhighlight lang="brush:xquery">
string(db:retrieve('multimedia', 'sample.avi'))
</presyntaxhighlight>
==HTTP Services==
* Resources can be deleted via <code>[[Commands#DELETE|DELETE]]</code>.
The [[Options#AUTOFLUSH{{Option|AUTOFLUSH]] }} option can be turned off before ''bulk operations'' (i.e. before a large number of new resources is added to the database).
The following commands create an empty database, add two resources, explicitly flush data structures to disk, and finally delete all inserted data:
<presyntaxhighlight>
CREATE DB example
SET AUTOFLUSH false
FLUSH
DELETE /
</presyntaxhighlight>
You may also use the BaseX-specific [[Database Module|XQuery Database Functions]] to create, add, replace, and delete XML documents:
<pre classsyntaxhighlight lang="brush:xquery">
let $root := "/path/to/xml/documents/"
for $file in file:list($root)
return db:add("database", $root || $file)
</presyntaxhighlight>
Last but not least, XML documents can also be added via the GUI and the ''Database'' menu.
