db file sequential read \u6570\u636e\u6587\u4ef6\u5355\u5757\u8bfb\uff0c\u6307\u7684\u662f\u4ece\u6570\u636e\u6587\u4ef6\u4e2d\u83b7\u53d6\u4e00\u4e2a\u5355\u5757\u7684\u4fe1\u606f\u3002\u6700\u80fd\u8ba9\u4eba\u60f3\u5230\u7684\u662f\u7d22\u5f15\u56de\u8868\uff0c\u5f53\u7136\u5168\u8868\u626b\u63cf\u4e5f\u53ef\u80fd\u4ea7\u751f\u5355\u5757\u8bfb\uff0c\u56e0\u4e3a\u4e0d\u662f\u6240\u6709\u7684\u5168\u8868\u626b\u63cf\u90fd\u80fd\u591a\u5757\u8bfb\u3002<\/p>
db file scattered read \u591a\u5757\u8bfb\uff0c\u6700\u5927\u5757\u6570\u7531db_file_multiblock_read_count\u5b9a\u4e49\uff0c\u6b64\u53c2\u6570\u901a\u5e38\u4e0e\u64cd\u4f5c\u7cfb\u7edfIO\u5927\u5c0f\u4e00\u81f4\uff0c\u64cd\u4f5c\u7cfb\u7edfIO\u4e00\u822c\u662f512K\u62161MB\u3002<\/p>
direct path read \u76f4\u63a5\u8def\u5f84\u8bfb\uff0c\u662f\u6307\u6570\u636e\u4e0d\u52a0\u8f7d\u5230\u6570\u636e\u7f13\u51b2\u533a(SGA\u7684\u4e00\u5757\u533a\u57df),\u76f4\u63a5\u52a0\u8f7d\u5230PGA\u3002db file sequential read\u548cdb file scattered read\u90fd\u662f\u5148\u5c06\u6570\u636e\u52a0\u8f7d\u5230\u6570\u636e\u7f13\u5b58\u533a\u3002\u76f4\u63a5\u8def\u5f84\u8bfb\u907f\u514d\u4e86\u6570\u636e\u7f13\u5b58\u533a\u7ba1\u7406\u7684\u5f00\u9500\u548c\u4e89\u7528\uff08\u8fd9\u662f\u5b83\u5b58\u5728\u7684\u539f\u56e0\uff09\uff0c\u4f46\u8bfb\u53d6\u7684\u6570\u636e\u4e0d\u80fd\u88ab\u5176\u4ed6\u7684\u8fdb\u7a0b\u4f7f\u7528\uff0c\u6362\u8a00\u4e4b\uff0c\u5176\u4ed6\u8fdb\u7a0b\u78b0\u5de7\u9700\u8981\u76f8\u540c\u7684\u5757\uff0c\u9700\u8981\u4ece\u78c1\u76d8\u91cd\u65b0\u8bfb\u53d6\u3002\u4e00\u4e0b\u573a\u666f\u4f1a\u4f7f\u7528\u76f4\u63a5\u8def\u5f84\u8bfb\uff1a<\/p>
\u6267\u884c\u4e34\u65f6\u6bb5IO\u65f6\u603b\u662f\u4f7f\u7528\u76f4\u63a5\u8def\u5f84\u8bfb\uff1b\u5e76\u884c\u67e5\u8be2\u65f6\u3002<\/p>
\u76f4\u63a5\u8def\u5f84\u8bfb\u53ef\u4ee5\u662f\u5355\u5757\u8bfb\u4e5f\u53ef\u4ee5\u662f\u591a\u5757\u8bfb\uff0c\u6267\u884c\u6709\u7d22\u5f15\u7684\u5355\u5757\u8bfb\u65f6\uff0cOracle\u504f\u597d\u7f13\u5b58IO\uff0c\u56e0\u4e3a\u5757\u5f88\u53ef\u80fd\u4f1a\u88ab\u91cd\u7528\u3002\u901a\u5e38\u76f4\u63a5\u8def\u5f84\u8def\u5f84\u8bfb\u66f4\u5e38\u7528\u591a\u5757\u8bfb\u3002<\/p>
direct path read\/write temp,\u5f53PGA\u6ca1\u6709\u8db3\u591f\u7684\u5185\u5b58\u65f6\uff0c\u5c31\u4f1a\u7528\u5230\u4e34\u65f6\u6bb5\u3002<\/p>
db file parallel write, DBWR IO\u88ab\u767b\u8bb0\u4e3a\u6b64\u4e8b\u4ef6\u3002DML\u64cd\u4f5c\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4f1a\u4fee\u6539\u6570\u636e\u7f13\u5b58\u533a\u7684\u6570\u636e\u5e93\uff0c\u7b49\u5f85\u68c0\u67e5\u70b9\u5230\u6765\u5c06\u810f\u5757\u5199\u5165\u5230\u78c1\u76d8\u3002<\/p>
direct path write,\u76f4\u63a5\u8def\u5f84\u5199\uff0c\u6570\u636e\u4ecePGA\u76f4\u63a5\u63d2\u5165\u5230\u6570\u636e\u6587\u4ef6\uff0c\u4e0d\u7ecf\u8fc7\u6570\u636e\u7f13\u5b58\u533a\u3002\u7528append\u6216\u8005\u5e76\u884c\u3002<\/p>
log file parallel write\uff0c\u5927\u90e8\u5206\u91cd\u505a\u65e5\u5fd7\u4f1a\u88ab\u6ce8\u518c\u4e3a\u6b64\u4e8b\u4ef6\u3002\u5f53\u91cd\u505a\u65e5\u5fd7\u521d\u59cb\u5316\u4e00\u4e2a\u65e5\u5fd7\u6587\u4ef6\uff0c\u4f1a\u767b\u8bb0log file single write\u548c log file sequential read.\u91cd\u505a\u65e5\u5fd7\u8bb0\u5f55\u5237\u5230\u78c1\u76d8\u65f6\uff0c\u4f1a\u6709log file sync\uff0c\u8fd9\u662f\u4e00\u4e2a\u91cd\u8981\u6307\u6807\uff0c\u901a\u5e38\u5e73\u5747\u65f6\u95f4\u8d85\u8fc720ms\uff0c\u5e94\u7528\u7cfb\u7edf\u5c31\u4f1a\u6709\u4e25\u91cd\u95ee\u9898\u4e86\u3002<\/p>
log archive I\/O \u5f52\u6863\u65e5\u5fd7\u5199\u88ab\u767b\u8bb0\u4e3a\u6b64\u4e8b\u4ef6\u3002\u5f52\u6863\u8fdb\u7a0b\u8bfb\u53d6\u975e\u6d3b\u52a8\u7684\u91cd\u505a\u65e5\u5fd7\u5e76\u5199\u5165\u5230\u5f52\u6863\u65e5\u5fd7\uff0c\u91cd\u505a\u65e5\u5fd7\u8bfb\u767b\u8bb0\u4e3alog file sequential read.<\/p>
flashback log file writes,\u5f53\u6062\u590d\u5199\u8fdb\u7a0b\u5199\u5165\u95ea\u56de\u65e5\u5fd7\uff0c\u4f1a\u767b\u8bb0\u4e3a\u6b64\u4e8b\u4ef6\u3002<\/p>
control file parallel write,control file sequential read,\u63a7\u5236\u6587\u4ef6IO\u767b\u8bb0\u7684\u7b49\u5f85\u4e8b\u4ef6\u3002<\/p>