Known limitations¶

This page is an index. Each limitation below is documented on the guide page it belongs to, and the link takes you to that section. The one-line summaries use the words of the linked section; when you need the detail or the workaround, follow the link. If an area is not listed, its guide page records no limitation.

Connectors and engines¶

Area	Limitation	Where it is documented
ClickHouse	On ClickHouse 25.8, `Date32` and `DateTime64` store only 1900-01-01 through 2299-12-31; a source value outside the column's range is not held by the replica, and the row is reported as a real difference.	ClickHouse - Known limits
ClickHouse	`Array`, `Map`, `Tuple`, `Nested`, `JSON` / `Object`, `Variant`, `Dynamic`, `IPv4` / `IPv6` and the aggregate-function types have no native rendering and take the slower reference path; no cross-engine verification has been recorded for these types.	ClickHouse - Known limits
ClickHouse	A container (`Array`, `Map` or `Tuple`) whose element is a `Date` or `DateTime` type is refused on the reference path as well; exclude such a column.	ClickHouse - Known limits
ClickHouse	Rounding modes other than half-up, numeric tolerance, float compare mode, canonical type override, timestamp rounding, a non-UTC timezone for naive timestamps, and transform chains other than `null_to_empty`, `empty_to_null` and `decimal_separator_normalize` are computed by the reference engine, not in ClickHouse.	ClickHouse - Known limits
ClickHouse	An in-SQL `decrypt_expression` is not supported; use a Python-side decryption algorithm (`decrypt_algo`) instead.	ClickHouse - Known limits
ClickHouse	`Distributed` tables under `FINAL` are not supported.	ClickHouse - Known limits
ClickHouse	TLS is verified with a private CA, not yet against ClickHouse Cloud; mutual TLS (client certificates) is not supported.	ClickHouse - Known limits
ClickHouse	ClickHouse Cloud has not been verified live yet.	ClickHouse - Known limits
ClickHouse	Hierarchical narrowing (segment filters) is not available on ClickHouse in this version.	ClickHouse - Known limits
ClickHouse	A `String` column holding bytes that are not valid UTF-8 stops the run with an error naming the column.	ClickHouse - Known limits
Delta Lake via Trino	Trino's `delta` catalog reads a Delta `TIMESTAMP` at millisecond precision; a passing run that reads such a column shows Pass - Reduced timestamp fidelity and never presents as a clean pass.	Delta Lake - Trino reads a Delta TIMESTAMP at millisecond precision
Delta Lake via Snowflake	Snowflake Delta Direct has refresh-driven visibility, no Row Tracking metadata, no change reads and a 1,000-commits-per-refresh vendor limit; `commit_snapshot` stays refused on Snowflake.	Delta Lake - Snowflake Delta Direct
Delta Lake via File Dataset	`delta` mode reads S3, GCS, ADLS and local paths only, under a reader-feature allowlist; a VACUUMed pin is refused, never read as latest.	Delta Lake - File dataset `delta` mode
Delta Lake mirrored as Iceberg	A Databricks UniForm table publishes its Iceberg metadata asynchronously after the Delta commit, so an Iceberg reader can briefly see an older commit.	Delta Lake - UniForm lag, Iceberg - UniForm metadata lag
Iceberg	With no SQL engine (DuckDB), equality deletes read only on unpartitioned format v2 tables with NULL-free equality columns of the proven types, and format v3 reads only unpartitioned tables without nanosecond timestamps, column defaults or deletion vectors (#3328); other shapes are refused by name.	Iceberg - What is not there yet
Systems	SAP Application and Kafka CDC Stream are shown as Future Release: visible but disabled, and cannot be configured.	Systems - Connectors

Comparison settings¶

Area	Limitation	Where it is documented
Key identity	V1 offers no case-insensitive identity profile and no accent-insensitive one.	Key identity - What is not offered in V1
FLOAT / DOUBLE columns	An exact FLOAT comparison runs on the DuckDB reference for Oracle, SQL Server, Snowflake, BigQuery, DB2 LUW and Redshift: still exact, but the raw values leave the warehouse instead of being hashed in place.	Float column handling - Current behavior
BLOB / binary columns	Metadata only is content-blind: a change that preserves length is invisible to it.	Field configuration - BLOB / binary columns
XML columns	The comparison is whitespace-significant: if the two sides pretty-print differently, every row will differ.	Field configuration - BLOB / binary columns
Encrypted columns	Some per-field overrides are disabled on encrypted columns for engine pairs where the decrypt cast is not yet byte-verified.	Field configuration - Encrypted columns
Field configuration editors	The three editing surfaces do not expose identical fields.	Field configuration - Things worth knowing

Replication tools¶

Area	Limitation	Where it is documented
Replication profiles	Most tools in the picker show Future Release and are disabled, including SAP SLT, SAP BODS and Qlik Replicate; with Custom / Other comparison stays fully accurate but tool-aware readiness is lost.	Replication profiles - Which tools are usable today

Evidence and consumption¶

Area	Limitation	Where it is documented
Evidence coverage	Evidence may not cover everything: sensitive columns may carry no values, what is stored is the comparison rendering rather than the original value, caps can truncate or skip the diff set, and evidence is a point in time.	Repair posture - Coverage limits
Reconciliation Consumption	Consumption is not priced, budgeted, reconciled to a provider invoice, or projected.	Reconciliation Consumption - What Paridity does not do
Reconciliation Consumption	Self-hosted engines have no provider meter, so their systems report usage only (for example bytes scanned) and are hidden from the Consumption page unless you turn on Show systems without a provider meter. Redshift node-hours and RPU-hours are not captured; Redshift reports bytes scanned only.	Reconciliation Consumption - Metered vs usage