AzureAzure Synapse AnalyticsAnalytics

`azurerm_synapse_sql_pool` cost estimation

A dedicated, provisioned data-warehouse pool. Priced per cDWU-hour by performance level, plus separately-billed storage, and pausable to stop compute charges.

An azurerm_synapse_sql_pool (formerly SQL Data Warehouse) is the provisioned, MPP data-warehouse engine inside Synapse Analytics. Its compute is measured in compute Data Warehouse Units (cDWU), and the performance level you pick (DW100c up to DW30000c) sets how many cDWUs run.

Compute bills per cDWU-hour at roughly $0.012/cDWU-hour. DW100c is 100 cDWU, so it runs about 100 x $0.012 x 730 = ~$876/month if left running continuously. The crucial cost lever is that a dedicated SQL pool can be paused: while paused, compute billing stops entirely and you pay only for storage. Many teams run pools only during business hours and save more than half.

c3x reads the sku_name (performance level) and prices cDWU-hours at 730 hours/month for a continuously-running pool. Storage bills separately per TB-month on the columnar store. Because the pause feature is so impactful, the estimate represents the always-on case; model an active-hours fraction in c3x-usage.yml to reflect a paused schedule.

Terraform example

A minimal but realistic configuration that C3X can estimate.

resource "azurerm_synapse_sql_pool" "warehouse" {
  name                 = "edw"
  synapse_workspace_id = azurerm_synapse_workspace.analytics.id
  sku_name             = "DW200c"
  storage_account_type = "GRS"
  create_mode          = "Default"
}

Pricing dimensions

What you actually pay for when you provision azurerm_synapse_sql_pool.

Dimension	Unit	What's being charged
Compute (cDWU)	per cDWU-hour	Compute Data Warehouse Units for the performance level, billed while the pool is running. DW100c = 100 cDWU. c3x assumes 730 hours/month unless paused. $0.012/cDWU-hour (~$876/mo for DW100c)
Storage	per TB-month	Columnar data storage, billed separately and continuously even when compute is paused. $23/TB-month (GRS)

Sample C3X output

Example output from c3x estimate (DW200c, running continuously):

azurerm_synapse_sql_pool.warehouse
└─ Compute (DW200c, 200 cDWU)   146,000  cDWU-hours    $1,752.00

OVERALL TOTAL                                          $1,752.00
(storage billed separately; pause to cut compute)

Optimization tips

Common ways to reduce azurerm_synapse_sql_pool cost without changing the workload.

Pause the pool outside business hours

Up to 70%

Paused pools incur zero compute charge, only storage. Running a pool 10 hours/weekday instead of 24/7 cuts compute by roughly 70%. Automate pause/resume on a schedule.

Right-size the performance level

Proportional to DW level

cDWU cost scales linearly with the DW level. Provision the lowest level that meets your query SLAs and scale up only for known heavy loads, scaling back down after.

Consider serverless SQL for ad-hoc querying

Whole pool for sporadic use

For exploratory or infrequent queries over data lake files, Synapse serverless SQL (pay-per-TB-scanned) avoids the always-on dedicated pool entirely.

FAQ

How does c3x estimate a Synapse dedicated SQL pool?

It reads sku_name (the DW performance level), derives the cDWU count, and prices cDWU-hours at 730 hours/month for a continuously-running pool. Storage is priced separately. Model a paused schedule via active hours in c3x-usage.yml.

Does pausing the pool really stop charges?

Compute charges stop entirely while paused; you pay only for storage. This is the single biggest cost lever for dedicated SQL pools, often more than halving the bill for business-hours workloads.

What does DW200c mean for cost?

DW200c provisions 200 cDWU. At ~$0.012/cDWU-hour that's about $1,752/month run continuously. Each step up the DW scale raises cost linearly with the cDWU count.

Is storage charged when paused?

Yes. Storage bills per TB-month continuously, paused or not. Only compute stops when you pause. Storage is usually a small fraction of the compute cost.

How is this different from Synapse serverless SQL?

A dedicated pool provisions fixed cDWU capacity billed by the hour. Serverless SQL charges per TB scanned with no provisioned capacity, better for ad-hoc or infrequent queries. Dedicated wins for steady, heavy warehouse workloads.