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

# Azure Synapse — What We Collect

> The metadata, observability signals, lineage, and quality results Prizm extracts from Azure Synapse.

Prizm reads from Synapse system views, the Synapse workspace APIs, and the storage behind your external tables. It never writes to Synapse. One physical table is one Prizm asset, so a table seen from two engines isn't duplicated.

**Catalog**

| Synapse object | What Prizm stores |
| :- | :- |
| Database / pool | Database asset |
| Schema | Schema asset |
| Table, view, and column | Table and view assets with each column's data type and nullability |
| Distribution (HASH, ROUND\_ROBIN, REPLICATE) | Distribution strategy and, for HASH, the distribution key column (Dedicated pool) |
| Index type | Index type (Dedicated pool) |
| Row count | Row count, summed across distributions (Dedicated pool) |
| Keys | Primary key, unique, and foreign key hints. Foreign keys aren't enforced in Synapse, so Prizm treats them as hints |
| External table | File format, storage path, and declared columns. The credential is stored as governance metadata only |
| Delta table | Schema, version, partitions, and commit history |
| Pipeline | Pipeline, with its folder, annotations, owner, schedule, last run and status, and activity list |
| Activity | Child of its pipeline |
| Trigger | Schedule metadata |
| Data flow | Child of its pipeline |

**Observability**

| Signal | How Prizm measures it |
| :- | :- |
| Volume | Partition statistics on Dedicated pools. On Serverless external tables the count can be estimated |
| Freshness | Dedicated pools have no native last-modified time, so Prizm compares row-count snapshots between runs. For Serverless external tables it uses the latest file modified time, and for Delta tables the latest commit time |
| Schema changes | Column differences between runs |
| Performance and usage | Query duration percentiles, waits, queue contention, and distribution skew on Dedicated pools. Query duration on Serverless |
| Pipeline runs | Status, duration, activity-level failures, and triggers that have stopped firing |

Synapse keeps only recent query history, so Prizm harvests it regularly and keeps its own record.

**Lineage**

Prizm builds table-level lineage from these sources, preferring what Synapse declares over what it infers:

1. Pipeline definitions (Copy and Data Flow activities)
2. View definitions, foreign keys, and external tables that point at a Delta path
3. `CTAS` and `CETAS` statements found in request history
4. Delta operation metadata

Lineage across surfaces joins on storage location, so multi-hop lineage and downstream impact are supported. Column-level lineage isn't covered.

**Quality & Criticality**

**Quality.** Structural, business, lookup, behavioral, and conditional checks run on your own compute: T-SQL on Dedicated pools, Serverless T-SQL for external tables, and Serverless for Delta tables. Serverless scans have a bytes budget, Dedicated pools have a concurrency cap, and Prizm labels its queries so you can identify them.

**Exceptions.** Failing records are written to an Iceberg table, partitioned by execution date and source table, and linked to the rule execution. Prizm never writes them back to Synapse.

**Criticality.** Each table gets a score from 0 to 100, shown as Critical (80 and above), High (60 to 79), Medium (40 to 59), or Low (below 40).

## What Prizm Does Not Collect

Prizm doesn't collect cost data, column-level lineage, or credentials stored in linked services. Request-history retention limits usage and `CTAS`/`CETAS` lineage to what Prizm has already harvested. CSV scans can't prune columns, so they use a stricter bytes budget.

## Next Steps

> **[Setup](/sources/synapse/setup)**
>
> Grant the permissions each item needs.

> **[FAQ](/sources/synapse/faq)**
>
> Common questions about the Synapse connector.


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