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Diffstat (limited to 'Doc/lib/libshelve.tex')
| -rw-r--r-- | Doc/lib/libshelve.tex | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/Doc/lib/libshelve.tex b/Doc/lib/libshelve.tex index 3e2bef9..0dec230 100644 --- a/Doc/lib/libshelve.tex +++ b/Doc/lib/libshelve.tex @@ -30,9 +30,26 @@ list = d.keys() # a list of all existing keys (slow!) d.close() # close it \end{verbatim} +Restrictions: + +\begin{itemize} + +\item +The choice of which database package will be used (e.g. dbm or gdbm) +depends on which interface is available. Therefore it isn't safe to +open the database directly using dbm. The database is also +(unfortunately) subject to the limitations of dbm, if it is used --- +this means that (the pickled representation of) the objects stored in +the database should be fairly small, and in rare cases key collisions +may cause the database to refuse updates. + +\item Dependent on the implementation, closing a persistent dictionary may or may not be necessary to flush changes to disk. -Note: \code{shelve} does not support {\em concurrent} access to +\item +The \code{shelve} module does not support {\em concurrent} access to shelved objects. Two programs should not try to simultaneously access the same shelf. + +\end{itemize} |