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Sharding VS Horizontal Partitioning



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Oracle Database commands

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Sharding Oracle Database

Sharding Oracle DB Source: https://www.oracle.com/technetwork/database/availability/sharding-faq-3610620.pdf • Sharding is for OLTP apps • Shards are distributed (but not necessarily replicated –unless you use Data Guard or GoldenGate for some Oracle instances) partitions (horizontal partitioning). • Shards reside on different Oracle instances, that may be of different releases (as long as the app is backward compatible with orlder Oracle DB versions) • The application believes there is only one Oracle instance: a sharded DB (SDB); but for better performances, it has to specify a shard-key (which is pretty much a partitioning key -e.g. customer ID, account nb , etc.) in the connection-string of the JDBC driver. The JDBC driver or connection pool will use this shard-key to provide a connection object for the relevant shard which contains the data pertinent to the required transaction [1] (i.e. not the whole Oracle instance). Note that there is a shard-routing-cache at the conn...

Datawarehouse notes

In a nutshell You put in a data-warehouse all the data of your enterprise. This data will be imported from diverse sources; and especially operational ones (e.g. the production database of your e-commerce website).   The goal of a DWH is to offer a single data-model (that usually sits within a relational DB), so that data-analysts can ultimately* create reports about the data, for “business people” (i.e. the decision makers of the company).   *Please note that data-analysts don’t directly work on the DWH; they work on data-marts . Data-marts are spin-offs of the DWH, but they usually only include a subset of the data, and have their data-models optimized for the specific type of analytics they will be submitted to. You will periodically load into your DWH data extracted from your many operational-sources. You will then do the same for your data-marts, which are used by data-analysts. Note that the yellow lines are d...