> ## Documentation Index
> Fetch the complete documentation index at: https://artie.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Definitions of key terms and concepts used throughout the Artie documentation.

A reference of terms and concepts you'll encounter when working with Artie.

## A

<AccordionGroup>
  <Accordion title="Ad hoc backfill">
    A manually triggered [backfill](/concepts/backfill) initiated from the pipeline overview, as opposed to the automatic backfill that runs during initial onboarding.
  </Accordion>
</AccordionGroup>

## B

<AccordionGroup>
  <Accordion title="Backfills">
    A process that copies existing historical data from a source table to the destination. Backfills run alongside ongoing CDC so that both current and historical rows are replicated.

    See the [Backfill guide](/concepts/backfill) for more details.
  </Accordion>

  <Accordion title="BYOC (Bring Your Own Cloud)">
    A deployment model where the [data plane](#d) runs inside your own cloud account or network while Artie hosts the [control plane](#c). This keeps all customer data within your infrastructure.
  </Accordion>
</AccordionGroup>

## C

<AccordionGroup>
  <Accordion title="CDC (change data capture)">
    Change data capture is a continuous process that captures inserts, updates, and deletes from a database's transaction log. Artie uses CDC to stream changes in near real-time to your destination.
  </Accordion>

  <Accordion title="Column encryption">
    Encrypting column values before writing them to the destination. Values can be decrypted later using either an Artie-managed key or a customer-provided KMS data encryption key (DEK). See [Tables](/tables/overview).
  </Accordion>

  <Accordion title="Column exclusion">
    A filter that replicates all columns except those in a specified list - useful for omitting PII or large unused columns. See [Column inclusion and exclusion](/guides/artie/column-inclusion-exclusion).
  </Accordion>

  <Accordion title="Column hashing">
    Replacing column values with a deterministic SHA-256 hash before writing to the destination. Hashed values are masked but remain joinable and stable across rows. See [Tables](/tables/overview).
  </Accordion>

  <Accordion title="Column inclusion">
    A filter that replicates only an explicit list of columns, excluding everything else by default. See [Column inclusion and exclusion](/guides/artie/column-inclusion-exclusion).
  </Accordion>

  <Accordion title="Control plane">
    The Artie-hosted layer responsible for the dashboard, orchestration, pipeline configuration, monitoring, and metrics. No customer row data passes through the control plane. See [Architecture](/concepts/architecture).
  </Accordion>

  <Accordion title="Compaction">
    Artie has an in-memory compaction mechanism that reduces the volume of writes sent to the destination by compacting multiple changes to the <Tooltip tip="identified by primary key">same row</Tooltip> before flushing.
    By doing so, Artie can reduce the number of writes sent to the destination.
  </Accordion>
</AccordionGroup>

## D

<AccordionGroup>
  <Accordion title="DocumentDB">
    Amazon DocumentDB is a fully managed, MongoDB-compatible document database service. Artie replicates data from DocumentDB via change streams and requires an [SSH tunnel](/connection-options/ssh-tunnel) since DocumentDB only allows access within your VPC. See the [DocumentDB source guide](/sources/documentdb).
  </Accordion>

  <Accordion title="Data plane">
    The environment where all data processing happens: reading from your source, buffering changes in Kafka, and writing to your destination. A data plane is scoped to a cloud provider and region. In BYOC deployments the data plane runs in your own network. See [Architecture](/concepts/architecture).
  </Accordion>

  <Accordion title="Destination table alias">
    A configurable name override that lets a source table appear under a different name in the destination. See [Tables](/tables/overview).
  </Accordion>
</AccordionGroup>

## F

<AccordionGroup>
  <Accordion title="Flush condition">
    One of three thresholds - time elapsed, deduplicated row count, or deduplicated byte size - that triggers a flush when any single condition is met. See [Flush rules](/concepts/flush-rules/overview).
  </Accordion>

  <Accordion title="Flushing">
    The process of writing buffered, in-memory data to the destination as an optimized batch, then committing the Kafka offset and resuming reads. See [Flush rules](/concepts/flush-rules/overview).
  </Accordion>
</AccordionGroup>

## H

<AccordionGroup>
  <Accordion title="History mode">
    A table setting that creates a companion `{TABLE}__HISTORY` table recording every insert, update, and delete for auditing and point-in-time analysis. See [Tables](/tables/overview#history-mode).
  </Accordion>
</AccordionGroup>

## M

<AccordionGroup>
  <Accordion title="Merge predicate">
    An additional destination column (such as a partition or cluster key) included in merge logic so the data warehouse can prune work during merges and improve performance. See [Tables](/tables/overview#use-a-merge-predicate).
  </Accordion>

  <Accordion title="Multi-step merge">
    For high-throughput OLAP destinations, splitting one large merge into sequential smaller steps to avoid timeouts on very large flush batches. See [Tables](/tables/overview#enable-multi-step-merge).
  </Accordion>
</AccordionGroup>

## P

<AccordionGroup>
  <Accordion title="Pipeline">
    A configured replication path from a source through Artie to a destination, including which tables to replicate and their individual settings.
  </Accordion>

  <Accordion title="PrivateLink">
    An AWS networking feature that provides private connectivity between VPCs without exposing traffic to the public internet. Artie supports PrivateLink as a [connection option](/connection-options/privatelink) for sources and destinations hosted in AWS.
  </Accordion>
</AccordionGroup>

## S

<AccordionGroup>
  <Accordion title="SSH tunnel">
    A secure, encrypted connection that forwards network traffic between Artie and a database through an intermediary host (such as a bastion or EC2 instance). See [SSH tunnel setup](/connection-options/ssh-tunnel).
  </Accordion>

  <Accordion title="Schema evolution">
    Automatic management of destination schema changes: adding new columns, optionally dropping columns that were removed upstream after a safety verification period and supporting column type changes.

    See the [Schema evolution guide](/guides/artie/schema-evolution) for more details.
  </Accordion>

  <Accordion title="Skip deletes">
    A table setting that causes Artie to ignore delete events so deleted source rows are not removed from the destination. See [Tables](/tables/overview#skip-deletes).
  </Accordion>

  <Accordion title="Soft deletes">
    A destination setting where deleted source rows are retained in the destination and flagged with a delete column (such as `__artie_delete`) instead of being physically removed.
  </Accordion>

  <Accordion title="Soft partitioning">
    Splitting rows into time-based physical tables (for example, monthly or daily) while exposing a single unified view for queries. See [Soft partitioning](/guides/artie/soft-partitioning).
  </Accordion>

  <Accordion title="System columns">
    Optional destination columns prefixed with `__artie_` that Artie adds for tracking operations, deletes, source metadata, and static tags. See [System columns](/tables/system-columns).
  </Accordion>
</AccordionGroup>

## T

<AccordionGroup>
  <Accordion title="Transparent column compression">
    Compressing column values in flight so large payloads fit within Kafka message size limits. Values are decompressed before landing in the destination, so the logical schema is unchanged. See [Tables](/tables/overview).
  </Accordion>
</AccordionGroup>

## U

<AccordionGroup>
  <Accordion title="Unified view">
    In soft partitioning, a database view that combines all partition tables using `UNION ALL` so consumers can query a single logical table name. See [Soft partitioning](/guides/artie/soft-partitioning).
  </Accordion>
</AccordionGroup>