Synnefo

Pithos requires to escape SQL wildcards in order to permit such characters in object paths.
Therefore, uses backslashes to escape like patterns
Issue #1768

However, Postgresql 8.4, contrary to the SQL standard, treats dy default baskslashes as escape characters
(this has been changed since postgresql 9.1 - standard_conforming_strings has become on dy default)
http://stackoverflow.com/questions/2106207/escape-sql-like-value-for-postgres-with-psycopg2#answer-2106443

As a result, it produces the following output:
WARNING: nonstandard use of \\ in a string literal at character 101
HINT: Use the escape string syntax for backslashes, e.g., E'\\'.

for SQL statements (constructed by sqlalchemy) such as:

SELECT nodes.node 
    FROM nodes 
    WHERE nodes.path LIKE E'c18088be-16b1-4263-8180-043c54e22903' ESCAPE '\\'

• pithos to use an escape character other than the backslash
  (that has a different behavior among the different databases)
  as proposed also here:
  http://www.postgresql.org/docs/8.4/static/sql-syntax-lexical.html#AEN1313

or

• to turn off postgresql escape_string_warning:
  http://www.postgresql.org/docs/8.4/static/runtime-config-compatible.html#GUC-ESCAPE-STRING-WARNING