stag-db.pl - Man Page
persistent storage and retrieval for stag data (xml, sxpr, itext)
Synopsis
stag-db -r person -k social_security_no -i ./person-idx myrecords.xml stag-db -i ./person-idx -q 999-9999-9999 -q 888-8888-8888
Description
Builds a simple file-based database for persistent storage and retrieval of nodes from a stag compatible document.
Imagine you have a very large file of data, in a stag compatible format such as XML. You want to index all the elements of type person; each person can be uniquely identified by social_security_no, which is a direct subnode of person
The first thing to do is to build an index file, which will be stored in your current directory:
stag-db -r person -k social_security_no -i ./person-idx myrecords.xml
You can then use the index "person-idx" to retrieve person nodes by their social security number
stag-db -i ./person-idx -q 999-9999-9999 > some-person.xml
You can export using different stag formats
stag-db -i ./person-idx -q 999-9999-9999 -w sxpr > some-person.xml
You can retrieve multiple nodes (although these need to be rooted to make a valid file)
stag-db -i ./person-idx -q 999-9999-9999 -q 888-8888-8888 -top personset
Or you can use a list of IDs from a file (newline delimited)
stag-db -i ./person-idx -qf my_ss_nmbrs.txt -top personset
Arguments
-i INDEXFILE
This file will be used as the persistent index for storage/retrieval
-r RELATION-NAME
This is the name of the stag node (XML element) that will be stored in the index; for example, with the XML below you may want to use the node name person and the unique key id
<person_set>
<person>
<id>...</id>
</person>
<person>
<id>...</id>
</person>
...
</person_set>This flag should only be used when you want to store data
-k UNIQUE-KEY
This node will be used as the unique/primary key for the data
This node should be nested directly below the node that is being stored in the index - if it is more that one below, specify a path
This flag should only be used when you want to store data
-u UNIQUE-KEY
Synonym for -k
-p PARSER
This can be the name of a stag supported format (xml, sxpr, itext) - XML is assumed by default
It can also be a module name - this module is used to parse the input file into a stag stream; see Data::Stag::BaseGenerator for details on writing your own parsers/event generators
This flag should only be used when you want to store data
-q QUERY-ID
Fetches the relation/node with unique key value equal to query-id
Multiple arguments can be passed by specifying -q multple times
This flag should only be used when you want to query data
-top NODE-NAME
If this is specified in conjunction with -q or -qf then all the query result nodes will be nested inside a node with this name (ie this provides a root for the resulting document tree)
-qf QUERY-FILE
This is a file of newline-seperated IDs; this is useful for querying the index in batch
-keys
This will write a list of all primary keys in the index
-w WRITER
This format will be used to write the data; can be any stag format (xml, sxpr, itext) - default XML.
Can also be a module that catches the incoming stag event stream and does something with it (for example, this could be a module you write yourself that transforms the stag events into HTML)
See Also
Data::Stag
For more complex stag to database mapping, see DBIx::DBStag and the scripts
stag-storenode
selectall_xml