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Diffstat (limited to 'docs/programmer_reference/transapp_filesys.html')
| -rw-r--r-- | docs/programmer_reference/transapp_filesys.html | 119 |
1 files changed, 68 insertions, 51 deletions
diff --git a/docs/programmer_reference/transapp_filesys.html b/docs/programmer_reference/transapp_filesys.html index 549dc2a7..70dbb49d 100644 --- a/docs/programmer_reference/transapp_filesys.html +++ b/docs/programmer_reference/transapp_filesys.html @@ -14,7 +14,7 @@ <body> <div xmlns="" class="navheader"> <div class="libver"> - <p>Library Version 11.2.5.3</p> + <p>Library Version 12.1.6.1</p> </div> <table width="100%" summary="Navigation header"> <tr> @@ -22,9 +22,7 @@ </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="transapp_journal.html">Prev</a> </td> - <th width="60%" align="center">Chapter 11. - Berkeley DB Transactional Data Store Applications - </th> + <th width="60%" align="center">Chapter 11. Berkeley DB Transactional Data Store Applications </th> <td width="20%" align="right"> <a accesskey="n" href="transapp_reclimit.html">Next</a></td> </tr> </table> @@ -38,60 +36,79 @@ </div> </div> </div> + <p> + The Berkeley DB API supports creating, removing and + renaming files. Creating files is supported by the <a href="../api_reference/C/dbopen.html" class="olink">DB->open()</a> + method. Removing files is supported by the <a href="../api_reference/C/envdbremove.html" class="olink">DB_ENV->dbremove()</a> and + <a href="../api_reference/C/dbremove.html" class="olink">DB->remove()</a> methods. Renaming files is supported by the + <a href="../api_reference/C/envdbrename.html" class="olink">DB_ENV->dbrename()</a> and <a href="../api_reference/C/dbrename.html" class="olink">DB->rename()</a> methods. (There are two methods + for removing and renaming files because one of the methods is + transactionally protected and one is not.) + </p> + <p> + Berkeley DB does not permit specifying the <a href="../api_reference/C/dbopen.html#open_DB_TRUNCATE" class="olink">DB_TRUNCATE</a> + flag when opening a file in a transaction-protected + environment. This is an implicit file deletion, but one that + does not always require the same operating system file + permissions as deleting and creating a file do. + </p> + <p> + If you have changed the name of a file or deleted it + outside of the Berkeley DB library (for example, you + explicitly removed a file using your normal operating system + utilities), then it is possible that recovery will not be able + to find a database to which the log refers. In this case, the + <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility will produce a warning message, saying it was + unable to locate a file it expected to find. This message is + only a warning because the file may have been subsequently + deleted as part of normal database operations before the + failure occurred, so is not necessarily a problem. + </p> <p> - The Berkeley DB API supports creating, removing and renaming files. - Creating files is supported by the <a href="../api_reference/C/dbopen.html" class="olink">DB->open()</a> method. Removing files is - supported by the <a href="../api_reference/C/envdbremove.html" class="olink">DB_ENV->dbremove()</a> and <a href="../api_reference/C/dbremove.html" class="olink">DB->remove()</a> methods. Renaming files - is supported by the <a href="../api_reference/C/envdbrename.html" class="olink">DB_ENV->dbrename()</a> and <a href="../api_reference/C/dbrename.html" class="olink">DB->rename()</a> methods. (There are - two methods for removing and renaming files because one of the methods - is transactionally protected and one is not.) -</p> - <p> - Berkeley DB does not permit specifying the <a href="../api_reference/C/dbopen.html#open_DB_TRUNCATE" class="olink">DB_TRUNCATE</a> flag when - opening a file in a transaction-protected environment. This is an - implicit file deletion, but one that does not always require the same - operating system file permissions as deleting and creating a file do. -</p> - <p> - If you have changed the name of a file or deleted it outside of the - Berkeley DB library (for example, you explicitly removed a file using - your normal operating system utilities), then it is possible that - recovery will not be able to find a database to which the log refers. - In this case, the <a href="../api_reference/C/db_recover.html" class="olink">db_recover</a> utility will produce a warning message, saying - it was unable to locate a file it expected to find. This message is - only a warning because the file may have been subsequently deleted as - part of normal database operations before the failure occurred, so is - not necessarily a problem. -</p> - <p> - Generally, any filesystem operations that are performed outside the - Berkeley DB interface should be performed at the same time as making a - snapshot of the database. To perform filesystem operations correctly, - do the following: -</p> + Generally, any filesystem operations that are performed + outside the Berkeley DB interface should be performed at the + same time as making a snapshot of the database. To perform + filesystem operations correctly, do the following: + </p> <div class="orderedlist"> <ol type="1"> <li> - <p>Cleanly shut down database operations.</p> - <p>To shut down database operations cleanly, all applications accessing -the database environment must be shut down and a transaction checkpoint -must be taken. If the applications are not implemented so they can be -shut down gracefully (that is, closing all references to the database -environment), recovery must be performed after all applications have -been killed to ensure that the underlying databases are consistent on -disk.</p> + <p> + Cleanly shut down database operations. + </p> + <p> + To shut down database operations cleanly, all + applications accessing the database environment must + be shut down and a transaction checkpoint must be + taken. If the applications are not implemented so they + can be shut down gracefully (that is, closing all + references to the database environment), recovery must + be performed after all applications have been killed + to ensure that the underlying databases are consistent + on disk. + </p> </li> - <li>Perform the filesystem operations; for example, remove or rename one or -more files.</li> <li> - <p>Make an archival snapshot of the database.</p> - <p>Although this step is not strictly necessary, it is strongly -recommended. If this step is not performed, recovery from catastrophic -failure will require that recovery first be performed up to the time of -the filesystem operations, the filesystem operations be redone, and then -recovery be performed from the filesystem operations forward.</p> + Perform the filesystem operations; for example, + remove or rename one or more files. + </li> + <li> + <p> + Make an archival snapshot of the database. + </p> + <p> + Although this step is not strictly necessary, it is + strongly recommended. If this step is not performed, + recovery from catastrophic failure will require that + recovery first be performed up to the time of the + filesystem operations, the filesystem operations be + redone, and then recovery be performed from the + filesystem operations forward. + </p> </li> - <li>Restart the database applications.</li> + <li> + Restart the database applications. + </li> </ol> </div> </div> |