DB2 table storage structure is a set of one or more VSAM datasets. The VSAM dataset is used to store the tables. A storage structure also called as a page set. In db2, all the databases, table spaces and index spaces will be referred as DB2 Objects. There are two types of storage structures based on the type of storage.
Data Sources
The data sources define where the database tables reside and where the software runs logic objects for the enterprise. Data sources can point to. A database in a specific location (for example, a local database, such as E1Local located in \E900\data, or an IBM i data library, such as PRODDATA), A specific machine in the enterprise that processes logic. Data source definitions are stored in the Data Source Master table (F98611). Workstations use a Common table F98611, which generally resides in the system data source on the enterprise server. Oracle's JD Edwards EnterpriseOne servers that process logic and request data require their own unique definitions for data sources; therefore, they have their own table F98611 in the server map data source. A least two sets of table F98611 exist. They reside in a centralized system data source normally kept on an enterprise server which is accessed by workstations, and in a server map data source, which each logic server requires.
Space management might not at first seem to be an area of relevance for high availability. However, if neglected, it can lead to downtime. For example, if a database object needs to expand, but is not able to do so, applications cannot continue writing to the database and you quickly have to make more space available. You can manage space for the SAP system with DB2 for z/OS using either of the following -
DB2 itself, known as "DB2-managed data" Data Facility Storage Management Subsystem (DFSMS), which is system-managed storage, known as "SMS-managed data. SAP does not support the DB2 method "user-managed data" for the SAP system. Storage Management Subsystem (SMS) is the IBM automated approach to managing auxiliary storage such as disk space. It uses software programs to manage data security, placement, migration, backup, recall, recovery, and deletion. Using these functions, SMS makes sure that current data is available when needed and obsolete data is removed from storage. In this section, both SMS-managed and DB2-managed data are described. Both options provide a high degree of automation. We recommend you to use SMS-managed data if possible. With DB2 for z/OS the data to be managed consists of. SAP and DB2 system data (tablespaces and indexspaces), DB2 bootstrap dataset (BSDS) Catalog and directory data
Data Source Names
Data source names that you define are names used to identify the data source. You should use a meaningful name for the data sources. For example, to indicate that you are storing business data for production users, the data source name could be Business Data - Prod. JD Edwards EnterpriseOne provides demonstration data source names at installation; you can use these for your own data sources. See JD Edwards EnterpriseOne Applications Release 9.0 Upgrade Guide (for your database and platform).
Data Source Definitions
The data source definition must contain information about the database and the server in which it is located. Different database management systems identify the databases in different ways. For example, you must identify Oracle databases by the Oracle SQL*Net V.2 connect string. You must identify databases that you access through ODBC by the ODBC data source name.
Storage Structure
To cope with the current and future demand of the increasing population for the food grains, it is emphasized to reduce the loss of food during and after harvest. Food grains are stored for varying periods to ensure proper and balanced public distribution throughout the year. Post-harvest losses in India are estimated to be around 10 per cent, of which the losses during storage alone are estimated to be 6.58 per cent.
But, with the advent of improved agricultural technology, the farmer can afford to store the grains for a longer period with minimum loss. For the best storage performance, The product must be thoroughly cleaned and graded, Dried to the safe storage moisture level of 10-12 % for food grains and 7-9% for oilseeds (on a wet basis) for a safe storage period of 6-12 months. Storage structures should be properly repaired, cleaned and disinfected, Structures should bear a load of grain stored and do not permit contact/exchange with outside humid air, Structures should be constructed in the coolest part of the house/ farm.
An ideal storage facility should satisfy the following requirements. It should provide maximum possible protection from ground moisture, rain, insect pests, moulds, rodents, birds, fore etc. It should provide the necessary facility for inspection, disinfection, loading, unloading, cleaning and reconditioning. It should protect grain from excessive moisture and temperature favourable to both insect and mould development, It should be economical and suitable for a particular situation.
The storage structure for sequence in existing incremental mining algorithms of sequential patterns is used to store the sequences that meet the support threshold. When the database is updated, the projected database needs to be constructed to find the sequential patterns in the updated database. In this paper, we propose the structure of sequence tree based on projected database, called sequence tree, and give the Stree_PS algorithm which is used to construct the sequence tree.
Sequence tree is a novel data storage structure, it is similar in structure to the prefix tree. But the sequence tree stores all the sequences in the original database. The path from the root node to any leaf node represents a sequence in the database. The structural characteristic of sequence tree makes it suitable for incremental sequential pattern mining. Experiments show that the incremental mining algorithm of sequential patterns which uses the sequence tree as the storage structure for sequences outperforms PrefixSpan in space cost on condition that the support threshold is smaller.