Softwr

Databases · head to head

Memcached vs TiDB

M

Memcached

Databases

Distributed memory object caching system

From
Free
Rated
-
Full reviewWebsite
TiDB logo

TiDB

Databases

Apache 2.0 distributed SQL database with MySQL wire compatibility and a separate columnar replica for analytical queries.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Memcached no persistence at all: restart a node and its cache is gone, which every design must assume; TiDB a production cluster needs several placement driver, storage and SQL nodes before it is fault tolerant, so the minimum viable footprint is far larger than a MySQL server and TiDB is never the economical choice for a small database.
  • They diverge on capability: Memcached covers In-memory key-value cache, TiDB covers MySQL wire compatibility.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Memcached and TiDB actually diverge.

Attributes where Memcached and TiDB differ
AttributeMemcachedTiDB
Pricing modelOpen source, no licence fee; managed cloud billed separatelyfreemium
PlatformsLinux, macOS, Windows, Docker, Self-hostedCloud, AWS, Azure, Google Cloud Platform, Self-managed
FoundedUnknown2015

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Databases).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Memcached

  • In-memory key-value cache
  • Multithreaded
  • Client-side sharding
  • Predictable memory use

Only in TiDB

  • MySQL wire compatibility
  • Horizontal write scaling
  • Distributed ACID transactions
  • TiFlash columnar replica
  • Automatic rebalancing
  • Raft replication
  • Apache 2.0 licence
  • Online schema change

What people use each for

The jobs each tool is most often brought in to do.

Memcached

  • Caching expensive database query results to cut loadnot TiDB
  • Session storage where losing sessions on restart is acceptablenot TiDB
  • Fronting an API whose responses are costly and change slowlynot TiDB

TiDB

  • A MySQL workload that has hit the write ceiling of a single primary and would otherwise need an application-level sharding layernot Memcached
  • Reporting that must run against current transactional data, where the columnar replica removes the delay and the cost of an ETL pipelinenot Memcached
  • Multi-region deployments needing a single logical database with automatic failover rather than manual primary promotionnot Memcached
  • Migrating off a sharded MySQL estate where the sharding logic in the application has become the main source of bugs and operational toilnot Memcached

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Memcached

  • No persistence at all: restart a node and its cache is gone, which every design must assume
  • No replication or failover, so losing a node loses that share of the cache
  • Only simple key-value, with none of the lists, sorted sets or streams Redis offers
  • Values are capped at 1MB by default, which surprises teams caching large documents

TiDB

  • A production cluster needs several placement driver, storage and SQL nodes before it is fault tolerant, so the minimum viable footprint is far larger than a MySQL server and TiDB is never the economical choice for a small database.
  • Every transaction takes a timestamp from the placement driver and crosses the network to storage nodes, so simple point queries are slower than on single-node MySQL and latency-sensitive paths need to be measured, not assumed.
  • MySQL compatibility is at the wire and dialect level but not complete; stored procedures, triggers and events are not supported, so an application that pushed logic into the database cannot simply be repointed.
  • The columnar replica is an extra full copy of the data on its own nodes, so hybrid analytics roughly doubles storage and adds hardware that must be sized and paid for separately.
  • Operating it well requires cluster-specific expertise in TiUP or the Kubernetes operator, region hot spots, and rebalancing behaviour, so the licence is free but the running cost includes an engineer who understands distributed storage.

Pricing, plan by plan

Memcached

Free
  • MemcachedFree
    • Full functionality
    • Self-hosted
    • No usage limits

TiDB

Free
  • ServerlessFree
    • 5GB storage
    • 50M request units
    • Free forever tier
  • Dedicated$250/month
    • Dedicated resources
    • SLA guarantees
    • Enterprise support

Which should you pick?

Choose Memcached if

  • You need in-memory key-value cache.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Self-hosted.
  • You also want multithreaded.
Memcached review

Choose TiDB if

  • You need mysql wire compatibility.
  • You want to start without paying.
  • You work on Cloud, AWS, Azure, Google Cloud Platform, Self-managed.
  • You also want horizontal write scaling.
TiDB review

Questions people ask

Is Memcached or TiDB better?
Neither clearly leads. Memcached starts at Free and TiDB at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Memcached or TiDB?
Memcached starts at Free and TiDB at Free.
Does Memcached or TiDB run on more platforms?
Memcached runs on Linux, macOS, Windows, Docker, Self-hosted. TiDB runs on Cloud, AWS, Azure, Google Cloud Platform, Self-managed.
Can I use Memcached for free?
Both have a free tier, so you can try either at no cost before committing.
What is Memcached best used for?
Memcached is most often used for caching expensive database query results to cut load, session storage where losing sessions on restart is acceptable, fronting an api whose responses are costly and change slowly. Of those, caching expensive database query results to cut load and session storage where losing sessions on restart is acceptable are not what TiDB is typically brought in for.
What can Memcached do that TiDB cannot?
Memcached covers In-memory key-value cache, Multithreaded, Client-side sharding, Predictable memory use. TiDB covers MySQL wire compatibility, Horizontal write scaling, Distributed ACID transactions, TiFlash columnar replica.

Answered from the vendors’ own pages

Memcached: Is Memcached free?

Yes, open source with no licence fee.

TiDB: Is TiDB a drop-in replacement for MySQL?

At the protocol and dialect level it is close, and most applications connect unchanged. Stored procedures, triggers and events are not supported, and latency characteristics differ, so it needs testing rather than assumption.

Memcached: Memcached or Redis?

Memcached is a pure cache: simpler, multithreaded and very predictable. Redis adds persistence, replication and rich data structures, which is why it is the default choice unless you specifically want a cache and nothing more.

TiDB: What licence is it under?

Apache 2.0, for both TiDB and the underlying TiKV storage engine. TiKV is a graduated CNCF project, which is a meaningful governance signal in a market where several competitors moved to source-available licences.

Memcached: Does Memcached persist data?

No. Everything is in memory and lost on restart, by design.

TiDB: Do I need TiFlash?

Only for analytical queries. It is an optional columnar replica; without it TiDB is a distributed transactional database. With it you get analytics on live data at the cost of an additional full copy.

TiDB: Is the managed cloud the same software?

TiDB Cloud runs the same engine, with the control plane, scaling and operational tooling provided as a service. The entry tier is metered differently from a dedicated cluster, so the cost model rather than the engine is what changes.

TiDB: When is TiDB the wrong choice?

When the database is small enough for one server, when latency on single-row lookups is the primary constraint, or when the application depends on MySQL stored procedures and triggers.

Share

Related pages

More on Memcached

More on TiDB

Keep looking

Other head to heads