Data Partitioning

What is Database Sharding?

Database sharding is a horizontal partitioning technique that splits a large dataset across multiple independent database servers (shards), where each shard ho…

How Do You Choose a Sharding Key?

A good sharding key is a column with high cardinality and an even, predictable value distribution that matches your query patterns, so writes and reads spread…

What is Range-Based Sharding?

Range-based sharding assigns rows to shards based on contiguous ranges of the shard key's value, so each shard owns a specific, ordered slice such as user IDs…

What is Hash-Based Sharding?

Hash-based sharding applies a hash function to the shard key and uses the result (typically modulo the shard count) to assign each row to a shard, which spread…

What is Consistent Hashing and Why Do Databases Use It?

Consistent hashing maps both shard keys and shard servers onto the same circular hash space, so each key is owned by the next server found clockwise on the rin…

What Are TimescaleDB Hypertables and How Do They Work?

A TimescaleDB hypertable is a PostgreSQL table that is automatically partitioned behind the scenes into many smaller physical tables called chunks, typically s…

What is Tiered Storage for Hot and Cold Data?

Tiered storage places data on different classes of storage medium based on how frequently it is accessed — hot data (frequently read/written) sits on fast, exp…

What Are Common Archival Strategies for Old Database Data?

Archival strategies move old, rarely accessed data out of the primary operational database into cheaper long-term storage — via time-based partition archiving,…

What is Consistent Hashing?

Consistent hashing is a distribution technique that maps both data keys and servers onto the same hash ring, so that when a server is added or removed only a s…

What is the Hot Partition Problem and How Do You Fix It?

The hot partition problem occurs when a partitioning scheme sends a disproportionate share of traffic to one shard — because the chosen partition key is skewed…

What Are the Main Data Partitioning Strategies?

Data partitioning splits a large dataset across multiple nodes using a strategy such as range partitioning (contiguous key ranges per node), hash partitioning…

What are the Main Database Sharding Strategies?

The main sharding strategies are range-based (splitting data by contiguous key ranges), hash-based (splitting data by a hash of the key), and directory-based (…

How Do You Rebalance Shards Without Downtime?

Rebalancing shards without downtime means gradually migrating a subset of data to new or less-loaded shards while keeping both the old and new locations correc…

How Does Rebalancing Work on a Consistent Hashing Ring?

Rebalancing on a consistent hashing ring means that when a node joins or leaves, only the keys sitting between the changed node and its immediate neighbor on t…

How Do You Design a Good Partition Key?

A good partition key spreads data and traffic evenly across all partitions (avoiding hot spots) while still keeping any data that must be read or ordered toget…

How Do You Mitigate Hot Spots in a Sharded System?

A hot spot is a single shard, partition, or key that receives disproportionately more traffic than its peers, and it is mitigated by spreading that skewed load…