CAP vs ELT

CAP (Consistency, Availability, Partition tolerance) and ELT (Extract, Load, Transform) both come up in technology conversations and get confused. Here's the plain-English difference, side by side, so you can use each one with confidence.

The key difference: CAP refers to consistency, availability, partition tolerance, while ELT refers to extract, load, transform — they describe different things even when they show up in the same sentence.

CAP — Consistency, Availability, Partition tolerance

Theorem stating a distributed system can guarantee only two of the three properties at once. CAP is the reason every serious system design discussion eventually comes back to trade-offs.

Full CAP definition →

ELT — Extract, Load, Transform

Modern variant where raw data is loaded into the warehouse first and transformed in-place using SQL. ELT is the cloud-warehouse default — cheaper storage, more flexible modeling.

Full ELT definition →

When to use CAP

Reach for "CAP" when the conversation is specifically about consistency, availability, partition tolerance. Theorem stating a distributed system can guarantee only two of the three properties at once. CAP is the reason every serious system design discussion eventually comes back to trade-offs.

When to use ELT

Reach for "ELT" when the conversation is specifically about extract, load, transform. Modern variant where raw data is loaded into the warehouse first and transformed in-place using SQL. ELT is the cloud-warehouse default — cheaper storage, more flexible modeling.

FAQs

What is the difference between CAP and ELT?

CAP stands for Consistency, Availability, Partition tolerance — Theorem stating a distributed system can guarantee only two of the three properties at once. CAP is the reason every serious system design discussion eventually comes back to trade-offs. ELT stands for Extract, Load, Transform — Modern variant where raw data is loaded into the warehouse first and transformed in-place using SQL. ELT is the cloud-warehouse default — cheaper storage, more flexible modeling.

Are CAP and ELT the same thing?

No. They're often used in the same conversation because they're related, but they describe different concepts. CAP = Consistency, Availability, Partition tolerance. ELT = Extract, Load, Transform.

When should I use CAP vs ELT?

Use CAP when you're specifically referring to consistency, availability, partition tolerance. Use ELT when the topic is extract, load, transform.