How to fix 2200N: invalid_xml_content in PostgreSQL

Before debugging in PostgreSQL, ensure your XML is well-formed using an external validator or the xmllint command:

xmllint --noout your-file.xml

If xmllint finds errors, fix the XML structure before attempting to load it into PostgreSQL. Common issues include unclosed tags, invalid characters, and encoding declarations.

If you are running PostgreSQL 15.1 or 15.2, upgrade to 15.3 or later. This version included a fix for the libxml2 buffer handling issue:

SELECT version();

Contact your database administrator or hosting provider (Railway, AWS RDS, Heroku) to perform the upgrade. After upgrading, retry your XML operation.

If your XML includes a DOCTYPE declaration, use XMLPARSE with DOCUMENT mode instead of CONTENT:

-- This will fail (default CONTENT mode doesn't allow DOCTYPE)
INSERT INTO my_table (xml_col) VALUES ('<?xml version="1.0"?><!DOCTYPE root SYSTEM "file.dtd"><root/>');;

-- This will succeed (DOCUMENT mode allows DOCTYPE)
INSERT INTO my_table (xml_col) VALUES (XMLPARSE(DOCUMENT '<?xml version="1.0"?><!DOCTYPE root SYSTEM "file.dtd"><root/>'));

If you don't need DOCTYPE validation, remove the DOCTYPE declaration from your XML.

If you are bulk-importing XML data using COPY, split large imports into chunks of 2000 records or fewer to avoid buffer overflow:

# Split a large CSV into 2000-line chunks
split -l 2000 large-file.csv chunk-

# Load each chunk separately
for f in chunk-*; do
  psql -c "COPY my_table FROM STDIN" < $f
done

Alternatively, from within the COPY protocol, call PQputCopyEnd() after every 2000 records to flush the buffer.

XML with special characters (e.g., unescaped &, <, >) or incorrect character encoding can trigger the error. Validate your XML is UTF-8 encoded and special characters are properly escaped:

-- Valid (properly escaped)
INSERT INTO my_table (xml_col) VALUES ('<root><item>&lt;escaped&gt;</item></root>');

-- Invalid (unescaped special character)
INSERT INTO my_table (xml_col) VALUES ('<root><item><unescaped></item></root>');

Use XMLPARSE to let PostgreSQL handle escaping more reliably.

Check your PostgreSQL server logs for additional context about which XML triggered the error:

# On Linux (assuming standard log location)
tail -f /var/log/postgresql/postgresql.log | grep 2200N

# Or via psql
SELECT pg_read_file('log/postgresql.log') LIKE '%2200N%';

The detailed error message may reveal the exact line in your XML that is problematic, helping you pinpoint the fix.