在PostgreSQL中，JSON数据类型的大小限制

Does anyone know what is the limit on the size of JSON data type in PostgreSQL 9.2?

有人知道PostgreSQL 9.2中JSON数据类型的大小的限制是什么吗?

1 个解决方案

#1

Looking at the source for PostgreSQL 9.2.1:

查看PostgreSQL 9.2.1的源代码:

Source: postgresql-9.2.1\src\backend\utils\adt\json.c:
/*
 * Input.
 */
Datum
json_in(PG_FUNCTION_ARGS)
{
    char       *text = PG_GETARG_CSTRING(0);

    json_validate_cstring(text);

    /* Internal representation is the same as text, for now */
    PG_RETURN_TEXT_P(cstring_to_text(text));
}

Update for PostgreSQL 9.3.5:

PostgreSQL 9.3.5更新:

The code has changed in the json_in function, but the json internal representation is still text:

在json_in函数中代码已经更改，但是json内部表示仍然是文本:

Source: postgresql-9.3.5\src\backend\utils\adt\json.c:
/*
 * Input.
 */
Datum
json_in(PG_FUNCTION_ARGS)
{
    char       *json = PG_GETARG_CSTRING(0);
    text       *result = cstring_to_text(json);
    JsonLexContext *lex;

    /* validate it */
    lex = makeJsonLexContext(result, false);
    pg_parse_json(lex, &nullSemAction);

    /* Internal representation is the same as text, for now */
    PG_RETURN_TEXT_P(result);
}

So it appears that, for now at least, json is the same as a text datatype but with JSON validation. The text datatype's maximum size is 1GB.

因此，至少现在看来，json与文本数据类型相同，但使用了json验证。文本数据类型的最大大小为1GB。

#1