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Description

The ORA-30185 error in Oracle Database indicates that the output string being generated is too large to fit into the allocated buffer. This typically occurs when using functions or procedures that return large amounts of data, exceeding the buffer's capacity.

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Error Message

ORA-30185: output too large to fit in the buffer

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Known Causes

3 known causes

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Insufficient Buffer Size

The buffer allocated to store the output string is smaller than the actual data being returned, leading to an overflow.

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Incorrect Length Parameter

The length parameter passed to the function or procedure is not large enough to accommodate the entire output string.

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Large Data Retrieval

The query or operation retrieves an unexpectedly large dataset, exceeding the buffer's capacity during processing.

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Solutions

3 solutions available

1. Increase PL/SQL CLOB or BLOB Buffer Size medium

Adjust PL/SQL initialization parameters to allow larger CLOB/BLOB data handling.

1

Connect to the Oracle database as a user with DBA privileges (e.g., SYS or SYSTEM).

2

Execute the following SQL statement to increase the size of the PL/SQL CLOB and BLOB buffers. The default is 1MB. You might need to adjust `32M` (32MB) based on your specific needs and available memory. Restarting the database instance is required for this change to take effect.

ALTER SYSTEM SET "PLSQL_CODE_CACHE_SIZE" = 32M SCOPE=SPFILE;
ALTER SYSTEM SET "PLSQL_NATIVE_LIBRARY_CACHE_SIZE" = 32M SCOPE=SPFILE;
-- Consider increasing these if the error persists or for very large data:
-- ALTER SYSTEM SET "JAVA_MAX_SESSION_SPACE" = 32M SCOPE=SPFILE;
-- ALTER SYSTEM SET "JAVA_SOFT_SESSIONSPACE" = 16M SCOPE=SPFILE;

3

After altering the SPFILE, restart the Oracle database instance for the changes to be applied.

2. Use DBMS_LOB Package for Chunked Processing advanced

Modify your PL/SQL code to process large LOB data in smaller chunks.

1

Identify the PL/SQL code that is generating the ORA-30185 error. This typically involves operations on CLOB or BLOB data types.

2

Refactor the code to use the `DBMS_LOB` package's functions for reading and writing LOB data in manageable chunks. Instead of attempting to load the entire LOB into a buffer at once, iterate through it using `DBMS_LOB.READ` and process each chunk.

DECLARE
  l_lob CLOB;
  l_buffer VARCHAR2(32767);
  l_amount INTEGER := 32767;
  l_offset INTEGER := 1;
BEGIN
  -- Assume l_lob is already populated
  LOOP
    DBMS_LOB.READ(l_lob, l_amount, l_offset, l_buffer);
    -- Process the l_buffer chunk here
    -- For example, append it to another LOB or write it to a file
    DBMS_OUTPUT.PUT_LINE('Processing chunk...');
    l_offset := l_offset + l_amount;
    EXIT WHEN l_amount < 32767;
  END LOOP;
EXCEPTION
  WHEN NO_DATA_FOUND THEN
    NULL; -- End of LOB
END;

3

For writing, use `DBMS_LOB.WRITEAPPEND` or `DBMS_LOB.WRITE` with appropriate offsets to append or write data chunk by chunk.

3. Increase Client-Side Buffer for SQL*Plus or SQL Developer easy

Adjust client tool settings to accommodate larger output.

1

If you are using SQL*Plus, increase the `SQL*Plus Buffer Size` parameter. This is often done by setting the `SET BUFFER` command before executing your query.

SET BUFFER 1000000 -- Set buffer to 1MB (adjust as needed)
SELECT large_clob_column FROM your_table WHERE ...;

2

If you are using SQL Developer, navigate to `Tools > Preferences > Database > Worksheet`. Under the 'SQL Worksheet' section, find `Fetch size` and increase it significantly. The default is often 1000. You can also adjust the `Maximum rows to display` if the issue is with displaying the result set.

3

For other client tools, consult their specific documentation for settings related to output buffer size or fetch size.

Oracle ORA-30185: Buffer Overflow