Rename core type 'blob' to 'bytes' for cross-database portability

Change the core binary type from 'blob' to 'bytes' to:
- Enable cross-database portability (LONGBLOB in MySQL, BYTEA in PostgreSQL)
- Free up native blob types (tinyblob, blob, mediumblob, longblob)
- Use Pythonic naming that matches the stored/returned type

Update all documentation to include PostgreSQL type mappings alongside
MySQL mappings, making the cross-database support explicit.

Co-authored-by: dimitri-yatsenko <dimitri@datajoint.com>

Author: claude

docs/src/design/tables/attributes.md

@@ -89,25 +89,26 @@ into a DataJoint pipeline.
 conversion between Python objects and database storage formats. Use this to store
 complex data types like graphs, domain-specific objects, or custom data structures.
 
-## Numeric type aliases
+## Core type aliases
 
-DataJoint provides convenient type aliases that map to standard MySQL numeric types.
+DataJoint provides convenient type aliases that map to standard database types.
 These aliases use familiar naming conventions from NumPy and other numerical computing
-libraries, making table definitions more readable and explicit about data precision.
-
-| Alias | MySQL Type | Description |
-|-------|------------|-------------|
-| `bool` | `tinyint` | Boolean value (0 or 1) |
-| `int8` | `tinyint` | 8-bit signed integer (-128 to 127) |
-| `uint8` | `tinyint unsigned` | 8-bit unsigned integer (0 to 255) |
-| `int16` | `smallint` | 16-bit signed integer (-32,768 to 32,767) |
-| `uint16` | `smallint unsigned` | 16-bit unsigned integer (0 to 65,535) |
-| `int32` | `int` | 32-bit signed integer |
-| `uint32` | `int unsigned` | 32-bit unsigned integer |
-| `int64` | `bigint` | 64-bit signed integer |
-| `uint64` | `bigint unsigned` | 64-bit unsigned integer |
-| `float32` | `float` | 32-bit single-precision floating point |
-| `float64` | `double` | 64-bit double-precision floating point |
+libraries, making table definitions more readable and portable across database backends.
+
+| Alias | MySQL | PostgreSQL | Description |
+|-------|-------|------------|-------------|
+| `bool` | `TINYINT` | `BOOLEAN` | Boolean value (0 or 1) |
+| `int8` | `TINYINT` | `SMALLINT` | 8-bit signed integer (-128 to 127) |
+| `uint8` | `TINYINT UNSIGNED` | `SMALLINT` | 8-bit unsigned integer (0 to 255) |
+| `int16` | `SMALLINT` | `SMALLINT` | 16-bit signed integer |
+| `uint16` | `SMALLINT UNSIGNED` | `INTEGER` | 16-bit unsigned integer |
+| `int32` | `INT` | `INTEGER` | 32-bit signed integer |
+| `uint32` | `INT UNSIGNED` | `BIGINT` | 32-bit unsigned integer |
+| `int64` | `BIGINT` | `BIGINT` | 64-bit signed integer |
+| `uint64` | `BIGINT UNSIGNED` | `NUMERIC(20)` | 64-bit unsigned integer |
+| `float32` | `FLOAT` | `REAL` | 32-bit single-precision float |
+| `float64` | `DOUBLE` | `DOUBLE PRECISION` | 64-bit double-precision float |
+| `bytes` | `LONGBLOB` | `BYTEA` | Raw binary data |
 
 Example usage:
 
@@ -122,6 +123,7 @@ class Measurement(dj.Manual):
     sample_count : uint32       # unsigned 32-bit counter
     sensor_flags : uint8        # 8-bit status flags
     is_valid : bool             # boolean flag
+    raw_data : bytes            # raw binary data
     """
 ```
 

docs/src/design/tables/customtype.md

@@ -161,8 +161,8 @@ The `dtype` property specifies how data is stored in the database:
 
 | dtype | Use Case | Stored Format |
 |-------|----------|---------------|
+| `"bytes"` | Raw binary data (core type) | Binary (LONGBLOB/BYTEA) |
 | `"longblob"` | Complex Python objects, arrays | Serialized binary |
-| `"blob"` | Smaller objects | Serialized binary |
 | `"json"` | JSON-serializable data | JSON string |
 | `"varchar(N)"` | String representations | Text |
 | `"int"` | Integer identifiers | Integer |

docs/src/design/tables/storage-types-implementation-plan.md

@@ -50,8 +50,8 @@ CORE_TYPES = {
     "uuid": (r"uuid$", "binary(16)"),
     # JSON
     "json": (r"json$", None),
-    # Binary (blob maps to longblob)
-    "blob": (r"blob$", "longblob"),
+    # Binary (bytes maps to longblob in MySQL, bytea in PostgreSQL)
+    "bytes": (r"bytes$", "longblob"),
     # Temporal
     "date": (r"date$", None),
     "datetime": (r"datetime$", None),

docs/src/design/tables/storage-types-spec.md

@@ -18,8 +18,8 @@ This document defines a three-layer type architecture:
 │                 Core DataJoint Types (Layer 2)                     │
 │                                                                    │
 │  float32  float64  int64  uint64  int32  uint32  int16  uint16    │
-│  int8  uint8  bool  uuid  json  blob  date  datetime              │
-│  char(n)  varchar(n)  enum(...)                                    │
+│  int8  uint8  bool  uuid  json  bytes  date  datetime             │
+│  char(n)  varchar(n)  enum(...)  decimal(n,f)                      │
 ├───────────────────────────────────────────────────────────────────┤
 │               Native Database Types (Layer 1)                      │
 │                                                                    │
@@ -54,56 +54,56 @@ MySQL and PostgreSQL backends. Users should prefer these over native database ty
 
 ### Numeric Types
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `int8` | 8-bit signed | `TINYINT` |
-| `int16` | 16-bit signed | `SMALLINT` |
-| `int32` | 32-bit signed | `INT` |
-| `int64` | 64-bit signed | `BIGINT` |
-| `uint8` | 8-bit unsigned | `TINYINT UNSIGNED` |
-| `uint16` | 16-bit unsigned | `SMALLINT UNSIGNED` |
-| `uint32` | 32-bit unsigned | `INT UNSIGNED` |
-| `uint64` | 64-bit unsigned | `BIGINT UNSIGNED` |
-| `float32` | 32-bit float | `FLOAT` |
-| `float64` | 64-bit float | `DOUBLE` |
-| `decimal(n,f)` | Fixed-point | `DECIMAL(n,f)` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `int8` | 8-bit signed | `TINYINT` | `SMALLINT` |
+| `int16` | 16-bit signed | `SMALLINT` | `SMALLINT` |
+| `int32` | 32-bit signed | `INT` | `INTEGER` |
+| `int64` | 64-bit signed | `BIGINT` | `BIGINT` |
+| `uint8` | 8-bit unsigned | `TINYINT UNSIGNED` | `SMALLINT` |
+| `uint16` | 16-bit unsigned | `SMALLINT UNSIGNED` | `INTEGER` |
+| `uint32` | 32-bit unsigned | `INT UNSIGNED` | `BIGINT` |
+| `uint64` | 64-bit unsigned | `BIGINT UNSIGNED` | `NUMERIC(20)` |
+| `float32` | 32-bit float | `FLOAT` | `REAL` |
+| `float64` | 64-bit float | `DOUBLE` | `DOUBLE PRECISION` |
+| `decimal(n,f)` | Fixed-point | `DECIMAL(n,f)` | `NUMERIC(n,f)` |
 
 ### String Types
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `char(n)` | Fixed-length | `CHAR(n)` |
-| `varchar(n)` | Variable-length | `VARCHAR(n)` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `char(n)` | Fixed-length | `CHAR(n)` | `CHAR(n)` |
+| `varchar(n)` | Variable-length | `VARCHAR(n)` | `VARCHAR(n)` |
 
 ### Boolean
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `bool` | True/False | `TINYINT` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `bool` | True/False | `TINYINT` | `BOOLEAN` |
 
 ### Date/Time Types
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `date` | Date only | `DATE` |
-| `datetime` | Date and time | `DATETIME` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `date` | Date only | `DATE` | `DATE` |
+| `datetime` | Date and time | `DATETIME` | `TIMESTAMP` |
 
 ### Binary Types
 
-The core `blob` type stores raw bytes without any serialization. Use `<djblob>` AttributeType
+The core `bytes` type stores raw bytes without any serialization. Use `<djblob>` AttributeType
 for serialized Python objects.
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `blob` | Raw bytes | `LONGBLOB` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `bytes` | Raw bytes | `LONGBLOB` | `BYTEA` |
 
 ### Other Types
 
-| Core Type | Description | MySQL |
-|-----------|-------------|-------|
-| `json` | JSON document | `JSON` |
-| `uuid` | UUID | `BINARY(16)` |
-| `enum(...)` | Enumeration | `ENUM(...)` |
+| Core Type | Description | MySQL | PostgreSQL |
+|-----------|-------------|-------|------------|
+| `json` | JSON document | `JSON` | `JSONB` |
+| `uuid` | UUID | `BINARY(16)` | `UUID` |
+| `enum(...)` | Enumeration | `ENUM(...)` | `VARCHAR` + check |
 
 ### Native Passthrough Types
 

src/datajoint/declare.py

@@ -34,8 +34,8 @@
     "uuid": (r"uuid$", "binary(16)"),
     # JSON
     "json": (r"json$", None),  # json passes through as-is
-    # Binary (blob maps to longblob)
-    "blob": (r"blob$", "longblob"),
+    # Binary (bytes maps to longblob in MySQL, bytea in PostgreSQL)
+    "bytes": (r"bytes$", "longblob"),
     # Temporal
     "date": (r"date$", None),
     "datetime": (r"datetime$", None),
@@ -456,7 +456,7 @@ def substitute_special_type(match, category, foreign_key_sql, context):
     Substitute special types with their native SQL equivalents.
 
     Special types are:
-    - Core DataJoint types (float32 → float, uuid → binary(16), blob → longblob, etc.)
+    - Core DataJoint types (float32 → float, uuid → binary(16), bytes → longblob, etc.)
     - ADAPTED types (AttributeTypes in angle brackets)
 
     :param match: dict containing with keys "type" and "comment" -- will be modified in place