technology Online Quiz - 1718

In storage networking context (specifically Fibre Channel SANs), fabric refers to the configuration and topology of interconnected switches that form the network. The fabric is the logical and physical arrangement of switches, ports, and zoning that enables communication between servers and storage. It's not just the cable, switch, hardware, or software alone - it's the entire configuration.

In SAN architecture, servers and storage are decoupled - servers connect to the SAN network and storage connects to the same network independently. You can expand storage without affecting servers, add servers without changing storage, and scale both independently. With DAS and JBOD, expansion directly impacts the server. NAS has some independence but SAN provides complete decoupling.

Load balancing across multiple paths distributes data traffic across available paths between initiator (server) and target (storage) to maximize throughput. By spreading the load, faster overall data transfer is achieved. Multipathing provides redundancy but not necessarily load distribution. Replication copies data to secondary sites. Clustering provides server failover.

SAN provides multiple levels of redundancy throughout the entire data path: redundant switches, multiple paths (via multipathing), redundant controllers in storage arrays, RAID within the storage, and often replicated storage at different locations. NAS has some redundancy but not as comprehensive. DAS and JBOD have minimal redundancy as they're directly attached with single paths.

iSCSI (Internet Small Computer System Interface) is a protocol that transports SCSI commands over TCP/IP networks. It allows block-level storage access over standard Ethernet networks instead of specialized Fibre Channel networks. Option B (SCSI over FC) is FC protocol itself, not iSCSI. Option C is vague and incorrect.

FC-SAN and iSCSI-SAN are both SAN architectures but differ in fundamental ways: FC uses Fibre Channel protocol over specialized fiber/copper networks with dedicated FC switches, while iSCSI uses standard TCP/IP over Ethernet. They differ in bandwidth characteristics (FC typically higher), switching technology (FC switches vs Ethernet switches), and the underlying protocol (FCP vs iSCSI/TCP/IP).

SAN (Storage Area Network) and NAS (Network Attached Storage) are two different storage architectures that can indeed be integrated in enterprise environments. SAN provides block-level storage access over Fibre Channel or iSCSI, while NAS provides file-level storage over Ethernet. Modern storage systems often support both protocols, allowing organizations to use each for appropriate workloads while maintaining a unified storage infrastructure.

When a lookup transformation is configured to use dynamic cache in Informatica (or similar ETL tools), only the equality operator (=) can be used in the lookup condition. Dynamic cache requires an exact match on the lookup key to determine whether to insert, update, or reject rows based on cache contents. Operators like <> or >= would require range comparisons that dynamic cache cannot efficiently support.

The Sorter transformation in Informatica is classified as an active transformation because it can change the number of rows that pass through it. When configured to use the 'Sort distinct rows' option, it removes duplicate rows, thereby reducing the row count. Active transformations are those that can change the data row count or transaction boundaries, unlike passive transformations which pass all rows through unchanged.

The Joiner transformation in Informatica does NOT match null values during join operations. Null values are treated as unequal to all other values, including other nulls. This behavior differs from SQL's ANSI standard where null comparisons return unknown (not true or false). If you need to match rows with null keys, you must handle them explicitly through expressions or filter conditions before the join.

The Update Strategy transformation in Informatica allows update strategy settings at both the Mapping level (default strategy for all rows) and the Session level (override or additional settings). At the Mapping level, you can set a default update strategy expression. At the Session level, you can configure properties like 'Treat source rows as' (Insert, Delete, Update, or Data Driven) and override mapping-level settings if needed.

While Update Strategy is the primary transformation for flagging rows, Custom (or Custom Transformation) can also be used to set row flags for insert, update, delete, and reject operations. Custom transformations allow you to write procedural code that can manipulate row flags based on complex business logic that might be difficult to express in Update Strategy expressions alone. This provides flexibility when complex conditional logic determines how rows should be treated.

The Integration Service in Informatica creates a Sorter cache when running a session that includes the Sorter transformation. This is a specialized cache type specifically designed for sorting operations. It's different from Index or Data caches used by other transformations like Lookup, Aggregator, or Joiner. The Sorter cache stores rows temporarily while performing the sort operation based on the specified sort keys.

In Sequence Generator transformation, CURRVAL is the NEXTVAL incremented by the configured value (increment by value). When NEXTVAL is called, it returns the current value and then increments by the specified increment value. CURRVAL then returns this incremented value. For example, if NEXTVAL returns 100 with an increment of 1, CURRVAL would be 101. This allows you to access both the value used and the next value in the sequence.

To join 4 tables using Joiner transformations in Informatica, you need 3 Joiner transformations. Joiner transformations only accept two input sources (master and detail). The process is hierarchical: join Tables A and B (Joiner 1), join that result with Table C (Joiner 2), then join that result with Table D (Joiner 3). Each joiner reduces the number of data streams by one, so for n tables, you need n-1 joiners.

In Business Objects (BO), the Designer console is specifically used for creating Universes - the semantic layer that maps database structures to business terminology. Desktop Intelligence is for reporting, CMC is for administration, and Rich Client is for report viewing/creation.

BIAR (Business Intelligence Archive Resource) is the file extension used for BO backup and archive files. This format contains exported universe, report, and other metadata objects. The other options are BO file types but not the backup extension.

Business Objects maintains repository databases that store universe metadata, security, and audit information. Built-in audit databases track user activity, report usage, and system events for compliance and governance reporting. This is a core BO feature.

BIAR stands for Business Intelligence Archive Resource, which is the file format for BO exports/backups. The other options are incorrect - 'Repository' doesn't fit the Archive context, and 'Integrated' is not the actual expansion.