refactor: remove text from core types, keep as native passthrough (#1318)

`text` is no longer a core DataJoint type. It remains available as a
native SQL passthrough type (with portability warning).

Rationale:
- Core types should encourage structured, bounded data
- varchar(n) covers most legitimate text needs with explicit bounds
- json handles structured text better
- <object> is better for large/unbounded text (files, sequences, docs)
- text behavior varies across databases, hurting portability

Changes:
- Remove `text` from CORE_TYPES in declare.py
- Update NATIVE_TEXT pattern to match plain `text` (in addition to
  tinytext, mediumtext, longtext)
- Update archive docs to note text is native-only

Users who need unlimited text can:
- Use varchar(n) with generous limit
- Use json for structured content
- Use <object> for large text files
- Use native text types with portability warning

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: dimitri-yatsenko

docs/src/archive/design/tables/attributes.md

@@ -34,10 +34,12 @@ Use these portable, scientist-friendly types for cross-database compatibility.
 
 -  `char(n)`: fixed-length string of exactly *n* characters.
 -  `varchar(n)`: variable-length string up to *n* characters.
--  `text`: unlimited-length text for long-form content (notes, descriptions, abstracts).
 -  `enum(...)`: one of several enumerated values, e.g., `enum("low", "medium", "high")`.
    Do not use enums in primary keys due to difficulty changing definitions.
 
+> **Note:** For unlimited text, use `varchar` with a generous limit, `json` for structured content,
+> or `<object>` for large text files. Native SQL `text` types are supported but not portable.
+
 **Encoding policy:** All strings use UTF-8 encoding (`utf8mb4` in MySQL, `UTF8` in PostgreSQL).
 Character encoding and collation are database-level configuration, not part of type definitions.
 Comparisons are case-sensitive by default.

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

@@ -75,7 +75,9 @@ MySQL and PostgreSQL backends. Users should prefer these over native database ty
 |-----------|-------------|-------|------------|
 | `char(n)` | Fixed-length | `CHAR(n)` | `CHAR(n)` |
 | `varchar(n)` | Variable-length | `VARCHAR(n)` | `VARCHAR(n)` |
-| `text` | Unlimited text | `TEXT` | `TEXT` |
+
+> **Note:** Native SQL `text` types (`text`, `tinytext`, `mediumtext`, `longtext`) are supported
+> but not portable. Prefer `varchar(n)`, `json`, or `<object>` for portable schemas.
 
 **Encoding:** All strings use UTF-8 (`utf8mb4` in MySQL, `UTF8` in PostgreSQL).
 See [Encoding and Collation Policy](#encoding-and-collation-policy) for details.

src/datajoint/declare.py

@@ -45,8 +45,6 @@
     # String types (with parameters)
     "char": (r"char\s*\(\d+\)$", None),
     "varchar": (r"varchar\s*\(\d+\)$", None),
-    # Unlimited text
-    "text": (r"text$", None),
     # Enumeration
     "enum": (r"enum\s*\(.+\)$", None),
     # Fixed-point decimal
@@ -78,7 +76,7 @@
         STRING=r"(var)?char\s*\(.+\)$",  # Catches char/varchar not matched by core types
         TEMPORAL=r"(time|timestamp|year)(\s*\(.+\))?$",  # time, timestamp, year (not date/datetime)
         NATIVE_BLOB=r"(tiny|small|medium|long)blob$",  # Specific blob variants
-        NATIVE_TEXT=r"(tiny|small|medium|long)text$",  # Text variants (use plain 'text' instead)
+        NATIVE_TEXT=r"(tiny|small|medium|long)?text$",  # Native text types (not portable)
         # Codecs use angle brackets
         CODEC=r"<.+>$",
     ).items()