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| author | Lorry Tar Creator <lorry-tar-importer@baserock.org> | 2015-02-17 17:25:57 +0000 |
|---|---|---|
| committer | <> | 2015-03-17 16:26:24 +0000 |
| commit | 780b92ada9afcf1d58085a83a0b9e6bc982203d1 (patch) | |
| tree | 598f8b9fa431b228d29897e798de4ac0c1d3d970 /docs/programmer_reference/am_verify.html | |
| parent | 7a2660ba9cc2dc03a69ddfcfd95369395cc87444 (diff) | |
| download | berkeleydb-master.tar.gz | |
Diffstat (limited to 'docs/programmer_reference/am_verify.html')
| -rw-r--r-- | docs/programmer_reference/am_verify.html | 76 |
1 files changed, 44 insertions, 32 deletions
diff --git a/docs/programmer_reference/am_verify.html b/docs/programmer_reference/am_verify.html index 4be61686..f3b1ced0 100644 --- a/docs/programmer_reference/am_verify.html +++ b/docs/programmer_reference/am_verify.html @@ -14,17 +14,16 @@ <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> - <th colspan="3" align="center">Database verification and salvage</th> + <th colspan="3" align="center">Database verification and + salvage</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="am_upgrade.html">Prev</a> </td> - <th width="60%" align="center">Chapter 3. - Access Method Operations - </th> + <th width="60%" align="center">Chapter 3. Access Method Operations </th> <td width="20%" align="right"> <a accesskey="n" href="am_sync.html">Next</a></td> </tr> </table> @@ -34,38 +33,51 @@ <div class="titlepage"> <div> <div> - <h2 class="title" style="clear: both"><a id="am_verify"></a>Database verification and salvage</h2> + <h2 class="title" style="clear: both"><a id="am_verify"></a>Database verification and + salvage</h2> </div> </div> </div> - <p>The <a href="../api_reference/C/dbverify.html" class="olink">DB->verify()</a> method verifies that a file, and any databases it may -contain, are uncorrupted. In addition, the method may optionally be -called with a file stream argument to which all key/data pairs found in -the database are output. There are two modes for finding key/data pairs -to be output:</p> + <p> + The <a href="../api_reference/C/dbverify.html" class="olink">DB->verify()</a> method verifies that a file, and any + databases it may contain, are uncorrupted. In addition, the + method may optionally be called with a file stream argument to + which all key/data pairs found in the database are output. + There are two modes for finding key/data pairs to be + output: + </p> <div class="orderedlist"> <ol type="1"> - <li>If the <a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> flag is specified, the key/data pairs in the -database are output. When run in this mode, the database is assumed to -be largely uncorrupted. For example, the <a href="../api_reference/C/dbverify.html" class="olink">DB->verify()</a> method will -search for pages that are no longer linked into the database, and will -output key/data pairs from such pages. However, key/data items that -have been marked as deleted in the database will not be output, as the -page structures are generally trusted in this mode.</li> - <li>If both the <a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> and <a href="../api_reference/C/dbverify.html#verify_DB_AGGRESSIVE" class="olink">DB_AGGRESSIVE</a> flags are -specified, all possible key/data pairs are output. When run in this mode, -the database is assumed to be seriously corrupted. For example, key/data -pairs that have been deleted will re-appear in the output. In addition, -because pages may have been subsequently reused and modified during -normal database operations after the key/data pairs were deleted, it is -not uncommon for apparently corrupted key/data pairs to be output in this -mode, even when there is no corruption in the underlying database. The -output will almost always have to be edited by hand or other means before -the data is ready for reload into another database. We recommend that -<a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> be tried first, and <a href="../api_reference/C/dbverify.html#verify_DB_AGGRESSIVE" class="olink">DB_AGGRESSIVE</a> only tried -if the output from that first attempt is obviously missing data items or -the data is sufficiently valuable that human review of the output is -preferable to any kind of data loss.</li> + <li> + If the <a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> flag is specified, the key/data + pairs in the database are output. When run in this mode, + the database is assumed to be largely uncorrupted. For + example, the <a href="../api_reference/C/dbverify.html" class="olink">DB->verify()</a> method will search for pages that + are no longer linked into the database, and will output + key/data pairs from such pages. However, key/data items + that have been marked as deleted in the database will not + be output, as the page structures are generally trusted in + this mode. + </li> + <li> + If both the <a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> and <a href="../api_reference/C/dbverify.html#verify_DB_AGGRESSIVE" class="olink">DB_AGGRESSIVE</a> flags + are specified, all possible key/data pairs are output. + When run in this mode, the database is assumed to be + seriously corrupted. For example, key/data pairs that have + been deleted will re-appear in the output. In addition, + because pages may have been subsequently reused and + modified during normal database operations after the + key/data pairs were deleted, it is not uncommon for + apparently corrupted key/data pairs to be output in this + mode, even when there is no corruption in the underlying + database. The output will almost always have to be edited + by hand or other means before the data is ready for reload + into another database. We recommend that <a href="../api_reference/C/dbverify.html#verify_DB_SALVAGE" class="olink">DB_SALVAGE</a> be + tried first, and <a href="../api_reference/C/dbverify.html#verify_DB_AGGRESSIVE" class="olink">DB_AGGRESSIVE</a> only tried if the output + from that first attempt is obviously missing data items or + the data is sufficiently valuable that human review of the + output is preferable to any kind of data loss. + </li> </ol> </div> </div> |