Database-Based DMS Concepts
This section provides information that help database administrators (DBAs) to understand the features and limitations of the database-based DMS solutions, including:
The documents information and contents are stored in the following four tables:
KNTA_DOCUMENTS: Used by all PPM DMS solutions (File System, PPM Database DMS, and PPM External Database DMS). It stores the documents information that is displayed in the References section of a PPM entity page, as well as the current "check out" status of the document.
The following three columns are only used during documents migration:
KNTA_DOCUMENT_VERSIONS: Stores the document version metadata, including filename, file size, extension, version comment, version check in date and user.
KNTA_DOCUMENT_TIP_CONTENTS: Stores a copy of the document metadata from the KNTA_DOCUMENTS table (document name, description, author, and so on) and the latest version, as well as the binary contents of the latest version of the document in BLOB column
DOC_CONTENTS for full-text indexing.
KNTA_DOCUMENT_HISTORY_CONTENTS: Stores a copy of the metadata from KNTA_DOCUMENT_VERSIONS, as well as the binary contents of all non-tip versions of documents in DOC_CONTENTS for full-text indexing.
Every time a new version of a document is checked in, the row related to this document is copied from the KNTA_DOCUMENT_TIP_CONTENTS table to the KNTA_DOCUMENT_HISTORY_CONTENTS table, and the document contents of the new version are updated in the DOC_CONTENTS column of the KNTA_DOCUMENT_TIP_CONTENTS table.
For details about these tables, see the Data Model Guide.
All binary documents contents are saved in the two DOC_CONTENTS columns (BLOB) of the KNTA_DOCUMENT_TIP_CONTENTS table and the KNTA_DOCUMENT_HISTORY_CONTENTS table.
These columns are using the PPM default CLOB tablespace upon creation. However, considering that the amount of data stored in attachments can be very large (up to tens of GB), you might prefer to store these attachments in a separate dedicated tablespace.
Though this is supported, we recommend you to change the tablespace of these columns before performing the migration, so that all documents can directly use the newly configured tablespace.
Note: You can use compressed tablespaces to store DMS documents. This could significantly reduce the space needed on the disk of PPM database.
By default, the full text search feature is not enabled with PPM Database DMS or PPM External Database DMS.
In order to enable full text search, DBAs must first create the TEXT indexes on documents contents and metadata, and modify a server parameter (from the Administrator Console of PPM). For detailed instructions, see Configuring Full Text Search in Database-Based DMS Solutions. PPM Server restart is not required.
Why not enable Full text search by default?
The PPM Database DMS or PPM External Database DMS solution relies on Oracle TEXT technology to perform full text search. There are multiple ways to configure the Oracle TEXT indexes, and DBAs shall choose which configuration suits their users' preferences best, especially in how often the indexes are updated.
Moreover, we recommend DBAs to create the indexes after you have completed migrating your documents, so that the indexes can be created in one run, having no impact on migration performance. As indexes creation is a database-intensive operation, it is also better to let DBAs decide when this operation should occur in order to minimize the impact on PPM users.
Note: Readers are assumed to be knowledgeable about Oracle TEXT. If that is not the case, it is recommended that you read the Oracle TEXT Application Developer's Guide or consult Oracle online documentation related to Oracle TEXT.