I am using MonetDB 11.19.9 and using a JSON field type in my database. I am new to MonetDB and experienced with SQL and databases. I find when I try to store some json strings that I think are valid json, the database complains on row insert. For example, the following don't work: insert into foo (jdata) values ('["a", "b\\c"]'); insert into foo (jdata) values ('{"abc": ""}'); The first problem is with the quoted backslash. The second problem is with the double quotes. If I remove the quoted backslash it works, likewise replace double quotes with null and it works. This is my table create: create table foo ( jdata json ); My read of the JSON spec is that this is legal JSON. Are there known issues with JSON support in MonetDB? Thank you, Michael Helmke