Remove source-specific references from sink and SDK docs

Author: atharvalade

core/connectors/sdk/README.md

@@ -106,9 +106,8 @@ preserve_structure = false
   - **`preserve_structure`**: Whether to preserve the original message structure during conversion
   - **`field_mappings`**: Mapping of field names for transformation (e.g., `"old_field" = "new_field"`)
 - **`unwrap_envelope`**: Extracts a nested JSON field and promotes it as the top-level payload.
-  Required when a source emits envelope-wrapped records (e.g., Postgres `DatabaseRecord` with
-  `table_name`, `operation_type`, `data`, etc.) and the downstream sink expects flat JSON
-  matching the target table schema (e.g., Iceberg, Delta).
+  Required when a source emits envelope-wrapped records (with metadata fields alongside a nested
+  data object) and the downstream sink expects flat JSON matching the target table schema.
   - **`field`**: The envelope key whose value becomes the new payload (e.g., `"data"`). Must not be empty.
 
 ```toml

core/connectors/sdk/src/transforms/unwrap_envelope.rs

@@ -23,10 +23,9 @@ use serde::{Deserialize, Serialize};
 /// Configuration for the UnwrapEnvelope transform.
 ///
 /// Extracts a nested JSON field from an envelope object and promotes it
-/// to the top-level payload. For example, given a source envelope with
-/// shape `{ table_name, operation_type, timestamp, data: { ... },
-/// old_data }`, setting `field = "data"` replaces the entire payload
-/// with the contents of `data`.
+/// to the top-level payload. For example, given an envelope with shape
+/// `{ metadata_a, metadata_b, data: { ... } }`, setting `field = "data"`
+/// replaces the entire payload with the contents of `data`.
 #[derive(Debug, Serialize, Deserialize)]
 pub struct UnwrapEnvelopeConfig {
     pub field: String,

core/connectors/sinks/iceberg_sink/README.md

@@ -83,23 +83,19 @@ Example:
 
 ## Source Compatibility
 
-The Iceberg sink expects flat JSON where each top-level key maps directly to a column in the
-target Iceberg table schema. Sources that wrap row data in an envelope (e.g., the Postgres
-source emits `DatabaseRecord` objects with `table_name`, `operation_type`, `timestamp`, `data`,
-and `old_data` fields) are **not** directly compatible — the Arrow JSON reader will map envelope
-keys to table columns, producing nulls or schema errors.
+The Iceberg sink expects **flat JSON** where each top-level key maps directly to a column in the
+target Iceberg table schema. Sources that wrap row data in an envelope (with metadata fields
+alongside a nested data object) are not directly compatible — the Arrow JSON reader will map
+envelope keys to table columns, producing nulls or schema errors.
 
-Use the `unwrap_envelope` transform to extract the inner data before it reaches the sink:
+If your source emits envelope-wrapped JSON, use the `unwrap_envelope` transform to extract the
+inner data field before it reaches the sink:
 
 ```toml
-[[streams]]
-stream = "postgres_stream"
-topic = "postgres_topic"
-schema = "json"
-
 [transforms.unwrap_envelope]
 enabled = true
 field = "data"
 ```
 
-Alternatively, configure the Postgres source with `payload_column` and `payload_format = "json_direct"` to bypass the envelope entirely — see the Postgres source README for details.
+Set `field` to the envelope key that contains the actual row data. See the SDK README and your
+source connector's documentation for details on the envelope shape.