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大家好,今天和大家聊聊,同时也会结合的知识进行补充,敬请关注。 心脏作为人体的重要器官,其正常跳动对生命至关重要。由于各种原因,心脏电生理学av block问题日益凸显,其中AV Block(房室传导阻滞)作为一种常见的心脏电生理学问题,严重威胁着患者的生命健康。本文将围绕AV Block展开,探讨其成因、诊断、治疗及预防措施,以期为临床医生及患者提供有益参考。 一、AV Block概述 AV Block,即房室传导阻滞,是指心脏的房室传导系统发生异常,导致心房与心室之间的电信号传导受阻。根据传导受阻的程度,AV Block可分为一度、二度和三度三种类型。其中,一度AV Block表现为心室率减慢,但心室与心房搏动同步;二度AV Block表现为部分心室搏动脱落,心室率进一步减慢;三度AV Block则表现为心房与心室完全脱节,心室率极度减慢。 二、AV Block的成因 1. 心肌缺血:冠状动脉供血不足导致心肌缺血,使心肌细胞受损,进而影响房室传导。 2. 心肌炎:病毒、细菌、自身免疫等因素引起的炎症反应,可导致心肌细胞受损,影响房室传导。 3. 药物副作用:某些药物如β受体阻滞剂、钙通道阻滞剂等,可抑制心脏传导系统,引起AV Block。 4. 先天性心脏病:先天性心脏病患者,如房间隔缺损、室间隔缺损等,由于心脏结构异常,可能导致房室传导受阻。 5. 老龄化:随着年龄增长,心脏传导系统逐渐老化,导致传导功能下降,易发av block生AV Block。 三、AV Block的诊断 1. 心电图:通过心电图检查,可明确诊断AV Block的类型及程度。 2. 心脏超声:心脏超声检查可观察心脏结构及功能,有助于诊断AV Block的病因。 3. 心脏电生理检查:通过心脏电生理检查,可评估心脏传导系统的功能,明确诊断AV Block。 四、AV Block的治疗 1. 药物治疗:针对病因,给予相应的药物治疗,如抗心肌缺血药物、抗炎药物等。 2. 起搏器植入:对于严重AV Block患者,可考虑植入起搏器,以维持心脏跳动。 3. 心脏手术:对于某些先天性心脏病患者,可考虑心脏手术,改善心脏结构,缓解AV Block。 五、AV Block的预防 1. 健康生活方式:保持良好的生活习惯,如戒烟限酒、合理饮食、适量运动等,有助于预防AV Block。 2. 定期体检:定期进行心脏检查,早期发现并治疗心脏疾病,降低AV Block的发生率。 3. 遵医嘱用药:对于有药物副作用引起AV Block的患者,应遵医嘱用药,避免自行停药或换药。 AV Block作为一种常见的心脏电生理学问题,对患者生命健康构成严重威胁。了解AV Block的成因、诊断、治疗及预防措施,有助于提高临床医生及患者的认识,降低AV Block的发病率,提高患者的生活质量。 通过treedump查看索引结构 语法格式:alter session set events'immediate trace name treedump level index_object_id' SQL> create table t1(c1 varchar2(10)); 表已创建。 SQL> create index i1 on t1(c1); 索引已创建。 SQL> select object_id from user_objects where object_name='I1'; OBJECT_ID ---------- 364492 SQL> alter session set events'immediate trace name treedump level 364492'; trace file内容: branch: 0xb0ae6ac 185263788(0: nrow: 2, level: 2) branch: 0xb11227c 185672316(-1: nrow: 460, level: 1) leaf: 0xb0ae6ad 185263789(-1: nrow: 317 rrow: 317) leaf: 0xb112153 185672019(0: nrow: 295 rrow: 295) leaf: 0xb0ae82f 185264175(1: nrow: 281 rrow: 281) ... leaf: 0xb11211e 185671966(457: nrow: 334 rrow: 334) leaf: 0xb0ae83c 185264188(458: nrow: 338 rrow: 338) branch: 0xb112280 185672320(0: nrow: 454, level: 1) leaf: 0xb112127 185671975(-1: nrow: 303 rrow: 303) leaf: 0xb0ae6d6 185263830(0: nrow: 304 rrow: 304) leaf: 0xb112165 185672037(1: nrow: 300 rrow: 300) ... leaf: 0xb0ae810 185264144(451: nrow: 398 rrow: 398) leaf: 0xb112143 185672003(452: nrow: 401 rrow: 401) ----- end tree dump 块av block的类别:分支块和叶子块块的rdba地址:十六进制和十进制 相对于上一级块结构的位置,从-1开始,root块从 0开始 nrows:所有的av block记录数量(包括已删除的) rrows:当前包含的记录数量 level:分支块的级别,叶子节点隐式为0 注意:oracle的btree index几乎总是平衡的。 怎样获取索引块的地址信息 oracle为我们提供了两个视图:dba_segments dba_extents.通过这两个视图,我们可以查询索引的root块地址. SQL> l 1* select tablespace_name,segment_space_management from dba_tablespaces where tablespace_name in('TS1','USERS') SQL>/ TABLESPACE_NAME SEGMEN ------------------------------------ TS1 MANUAL USERS AUTO SQL> col segment_name for a20 SQL> col tablespace_name for a20 SQL> select segment_name,tablespace_name,header_file,header_block from dba_segments where owner='EASYPOINT' and segment_name like'I%' 2/ SEGMENT_NAME TABLESPACE_NAME HEADER_FILE HEADER_BLOCK --------------------------------------------------------------- I1 USERS 44 714411 I2 TS1 46 17 SQL> select segment_name,min(extent_id),min(block_id) from dba_extents where owner='EASYPOINT' and segment_name like'I%' group by segment_name; SEGMENT_NAME MIN(EXTENT_ID) MIN(BLOCK_ID) ----------------------------------------------- I2 0 17 I1 0 714409 SQL> SELECT DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(192938002) FROM DUAL; DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(192938002) ------------------------------------------------ 18 SQL> SELECT DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(185263788) FROM DUAL; DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(185263788) ------------------------------------------------ 714412 从这个地方我们可以看出,root索引块的地址为dba_segments中 header_block加1,在ASSM下,首extent的前2个数据块保存位图信息,第三个数据块为header_block.在mssm下,首extents的第一个数据块即为HEADER_BLOCK. 查看索引块信息 语法格式:alter system dump datafile file_id block block_id; alter system dump datafile file_id block min block_id block max block_id; dump root branch: SQL> select dbms_utility.data_block_address_block(185263788) c1,dbms_utility.data_block_address_file(185263788) c2 from dual; C1 C2 ---------------- 714412 44 SQL> oradebug setmypid 已处理的语句 SQL> oradebug tracefile_name /oracle/admin/orcl/udump/orcl_ora_73926.trc SQL> alter system dump datafile 44 block 714412; 系统已更改。 trace file内容 *** 2013-12-13 11:52:38.766 Start dump data blocks tsn: 4 file#: 44 minblk 714412 maxblk 714412 buffer tsn: 4 rdba: 0x0b0ae6ac(44/714412) scn: 0x0012.4a18d046 seq: 0x01 flg: 0x06 tail: 0xd0460601 frmt: 0x02 chkval: 0xacfe type: 0x06=trans data Hex dump of block: st=0, typ_found=1 Dump of memory from 0x0000000110432000 to 0x0000000110434000 110432000 06A20000 0B0AE6AC 4A18D046 00120106 [........J..F....] 110432010 ACFE0000 02030022 00058FCC 4A18D044 [......."....J..D] 110433FB0 024846FE 0B0AE6AF 02545AFE 0B112280 [.HF......TZ...".] 110433FC0 024E4BFE 31322F31 32303639 07787005 [.NK.12/12069.xp.] 110433FD0 19101A35 272F6F72 61636C65 2F61646D [...5'/oracle/adm] 110433FE0 696E2F6F 72636C2F 6264756D 702F616C [in/orcl/bdump/al] 110433FF0 6572745F 6F72636C 2E6C6F67 D0460601 [ert_orcl.log.F..] Block header dump: 0x0b0ae6ac Object id on Block? Y seg/obj: 0x58fcc csc: 0x12.4a18d044 itc: 1 flg: E typ: 2- INDEX brn: 0 bdba: 0xb0ae6a9 ver: 0x01 opc: 0 inc: 0 exflg: 0 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0006.006.000492f3 0x008130ca.aee2.01-BU- 1 fsc 0x0000.4a18d046 Branch block dump ================= header address 4567801932=0x11043204c kdxcolev 2 KDXCOLEV Flags=--- kdxcolok 1 kdxcoopc 0x83: opcode=3: iot flags=--- is converted=Y kdxconco 2 kdxcosdc 2 kdxconro 1 kdxcofbo 30=0x1e kdxcofeo 8048=0x1f70 kdxcoavs 8018 --kdxbrlmc 185672316=0xb11227c kdxbrsno 491 kdxbrbksz 8056 kdxbr2urrc 0 --row#0[8048] dba: 185672320=0xb112280 col 0; len 2;(2): 4e 4b col 1; TERM ----- end of branch block dump----- End dump data blocks tsn: 4 file#: 44 minblk 714412 maxblk 714412 dump leaf block: SQL> SELECT DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(185263789) FROM DUAL; DBMS_UTILITY.DATA_BLOCK_ADDRESS_BLOCK(185263789) ------------------------------------------------ 714413 SQL> alter system dump datafile 44 block 714413; 系统已更改。 tracefile内容: *** 2013-12-13 12:20:29.107 Start dump data blocks tsn: 4 file#: 44 minblk 714413 maxblk 714413 buffer tsn: 4 rdba: 0x0b0ae6ad(44/714413) scn: 0x0012.4a19790f seq: 0x01 flg: 0x06 tail: 0x790f0601 frmt: 0x02 chkval: 0xcff9 type: 0x06=trans data Hex dump of block: st=0, typ_found=1 Dump of memory from 0x0000000110432000 to 0x0000000110434000 110432000 06A20000 0B0AE6AD 4A19790F 00120106 [........J.y.....] 110432010 CFF90000 02000000 00058FCC 4A19790E [............J.y.] 110432020 00120058 00023200 0B0AE6A9 00060000 [...X..2.........] 110432030 00049288 008128AC AEE10100 C0000012 [......(.........] ... 110433FB0 E8BB01CC 00000641 41565A4F 45060B0A [.......AAVZOE...] 110433FC0 E74200A1 0717021C 3C020F02 C10602C1 [.B......<.......] 110433FD0 120D7871 0B081701 0B21A1DD 001C3C02 [..xq.....!....<.] 110433FE0 C10B02C1 0B018001 80018001 80FFFF01 [................] 110433FF0 800180FF 0778710B 0717021C 790F0601 [.....xq.....y...] Block header dump: 0x0b0ae6ad Object id on Block? Y seg/obj: 0x58fcc csc: 0x12.4a19790e itc: 2 flg: E typ: 2- INDEX brn: 0 bdba: 0xb0ae6a9 ver: 0x01 opc: 0 inc: 0 exflg: 0 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0006.000.00049288 0x008128ac.aee1.01 CB-- 0 scn 0x0012.4a184c24 0x02 0x0008.025.0003bd64 0x00813810.8882.06--U- 1 fsc 0x0000.4a19790f Leaf block dump =============== header address 4567801956=0x110432064 kdxcolev 0 KDXCOLEV Flags=--- kdxcolok 0 kdxcoopc 0x80: opcode=0: iot flags=--- is converted=Y kdxconco 2 kdxcosdc 10 kdxconro 317 kdxcofbo 670=0x29e kdxcofeo 2960=0xb90 kdxcoavs 2290 kdxlespl 0 kdxlende 0 kdxlenxt 185672019=0xb112153 kdxleprv 0=0x0 kdxledsz 0 kdxlebksz 8032 row#0[3712] flag:------, lock: 0, len=16 col 0; len 6;(6): 41 41 41 42 43 53 col 1; len 6;(6): 0b 11 22 f9 00 95 row#1[4464] flag:------, lock: 0, len=16 col 0; len 6;(6): 41 41 41 43 47 4c col 1; len 6;(6): 0b 0a e8 94 00 20 ... row#315[8000] flag:------, lock: 0, len=16 col 0; len 6;(6): 41 41 56 58 58 44 col 1; len 6;(6): 0b 0a e8 bb 01 cc row#316[8016] flag:------, lock: 0, len=16 col 0; len 6;(6): 41 41 56 5a 4f 45 col 1; len 6;(6): 0b 0a e7 42 00 a1 ----- end of leaf block dump----- End dump data blocks tsn: 4 file#: 44 minblk 714413 maxblk 714413 tracefile格式解析: 块头区域: rdba:相对数据块地址 scn:修改块的最后scn号 seq:在当前scn号下,数据块改变的次序 tail: scn的最后两个字节 frmt:数据块的格式(02 represents a post Oracle8 block format, A2 10g format) chkval:校验av block和 type: 06– transactional data block type(table/index/cluster) Hex dump of block: only displayed on later versions of Oracle seg/obj– object id csc: commit/cleanout SCN itc: interested transaction count(defaults 1 branch block, 2 leaf blocks) typ– block type(2– index) Itl– Interested Transaction Location: Itl: slot id, Xid: transaction id, Uba: undo block address, Flag: state of current transaction(C– Committed) Lck: number of locks help by current transaction Scn/Fsc: scn/fsc of current transaction kdxcolev: index level(0 represents leaf blocks) kdxcolok: denotes whether structural block transaction is occurring kdxcoopc: internal operation code kdxconco: index column count kdxcosdc: count of index structural changes involving block kdxconro: number of index entries(does not include kdxbrlmc pointer) kdxcofbo: offset to beginning of free space within block kdxcofeo: offset to the end of free space(i.e.. first portion of block containing index data) kdxcoavs: available space in block(effectively area between kdxcofbo and kdxcofeo) 分支块专用头信息 kdxbrlmc: block address if index value is less than the first(row#0) value(例如在root块中,明明有两条记录,却只包含一个row,这是因为第一个可以通过dkxbrlmc来确定) kdxbrsno: last index entry to be modified kdxbrbksz: size of usable block space 叶子块专有头信息 kdxlespl: bytes of uncommitted data at time of block split that have been cleaned out kdxlende: number of deleted entries kdxlenxt: pointer to the next leaf block in the index structure via corresponding rba kdxleprv: pointer to the previous leaf block in the index structure via corresponding rba Kdxledsz: deleted space kdxlebksz: usable block space(by default less than branch due to the additional ITL entry) 记录区域: branch entity Row number(starting at#0) followed by [starting location in block] followed by the dba Column number(starting at 0) followed by column length followed by column value Repeated for each indexed column Repeated for each branch entry 和的内容到此为止,期待下次与您分享更多内容! btree索引怎么创建oracle