ver-2.1.0.0

Release Notes

FIX BUGS:
[TD-2915]: python connector cursor iter next() function. (#5875)
[TD-3580]: taosdump support human readable time format. (#5888)
[TD-3639]: compare timestamp with datetime in python (#5940)
[td-3779]: fix bug during filter data block when handling last query.
[TD-3801]: taosdump coverity scan issue. (#5844)
[TD-3827]: taosdemo query argument miss lead segfault. (#5848)
[TD-3833]: taosdemo command line argument miss lead segfault. (#5859)
[TD-3850]: fix vnode write enqueue flowctrl UAF & no response
[TD-3851]: taosdemo performance boost. (#5857)
[TD-3872]: fix taosGetDiskSize statvfs input directory bug
[td-3874]: enable the value of UINT64_MAX-1 to be the valid tag values.
[td-3878]: fix the unsigned number bug in group by query.
[TD-3880]: C# driver test miss unsigned type. (#5871)
[TD-3883]: [http/clear parser] clear parser when decode finished
[TD-3906]: taosdemo back to 4 INT columns. (#5883)
[TD-3909]: [http/race] fix singleCmd race issue
[TD-3913]: mips compile support. (#5894)
[TD-3914]: taosdemo input argument validation. (#5899)
[TD-3915]: reduce taos client diagnose output. (#5898)
[TD-3944]: make default offline threshold to 10 days. (#5912)
[TD-3944]: make default offline threshold to 10 days. (#5913)
[td-3951]: check the input value of big int which is overflowed.
[TD-3968]: taosdemo data length should be 16*1024 (#5926)
[TD-3969]: taosdemo re-enable batch-create-tbl-num (#5932)
[TD-3985]: taosdemo timestamp step overflow. (#5946)

ENHANCEMENTS:
Revert "[TD-3079]: use multi-level storage with vnode's wal files"
[TD-3572]: response out of dnodes if #dnodes <= maxDbReplica
[td-3941]: refactor having operator.
[TD-3983]: update driver-go submodule to latest (#5945)

NEW FEATURES:
[td-2859]: support nest query.

DOCS:
[TD-1316]: "apercentile" func can be applied on super table.
[TD-2639]: fix lib name typo.
[TD-2639]: fix minor typo.
[TD-2639]: fix url link format.
[TD-2639]: remove ambiguous description about select expression.
[TD-2639]: update description about performance testing tools for inserting.
[TD-3611]: fix description about function top & bottom.
[TD-3666]: add notes about Binary type.
[TD-3666]: distinguish bytes & chars in length calculation.
[TD-3666]: should avoid storing multi-bytes chars in Binary.
[TD-3666]: update description about Binary column.
[TD-3869]: add notes about "TAOS_SUBSCRIBE_CALLBACK".
[TD-3944]: update default value for "offlineThreshold".
[TD-3984]: describe "union all" clause.
[TD-850]: describe limitation about calculation between columns.
[TD-850]: describe usage limitation about calculation expression.
[TD-850]: fix typo.

TEST:
[TD-3414]: add insert function with json files of taodemo-testcase
[TD-3414]: add insert function with json files of taodemo-testcase -repeat
[TD-3453]:modify filepath in scripts
[TD-3800]: add test case for query last(*)
[TD-3937]: add taosdemo performance test compare scripts

ver-2.0.20.0

Release Notes

FIX BUGS:
[TD-2976]: check 1970 timestamp support in C# taosdemo (#5813)
[TD-3162]: taos shell command line arugments. (#5810)
[TD-3204]: support usigned integer types for C# connector (#5808)
[TD-3317]: taosdemo interlace insertion. (#5774)
[td-3350]: Remove the illegal abort operation in case of multithread environment for sim.
[TD-3579]: sort mnode syncCfg nodeInfo to fix leader election failure
[TD-3607]: fix taosdemo limit and offset. (#5707)
[TD-3636]: fix taosdemo outorder range algorithm. (#5736)
[td-3664]:fix bug in top/bottom query.
[TD-3681]: fix syncdb precondition checkings
[TD-3682]: Insufficient disk space may cause oom
[TD-3683]: reduce buffer size for more stable table creation. (#5719)
[TD-3683]: reduce buffer size for more stable table creation. (#5720)
[TD-3705]: taosdemo columns or tags count overflow. (#5745)
[TD-3705]: taosdemo columns or tags count overflow. (#5745) (#5760)
[TD-3706]: [mnode] validate super table columns and tags count
[TD-3710]: [sync/memory] fix peer connection invalid read post freeing
[TD-3715]: taosdemo interlace rows must less than insert rows. (#5743)
[TD-3722]: taosdemo performance regression due to always set random seed. (#5740)
[TD-3733]: taosdemo buffer processing refactor. (#5766)
[TD-3741]: python test case on arm32. (#5767)
[TD-3752]: taosdemo columns+tags+ts must less then 1024. (#5782)
[TD-3758]: fix setnull throw exception when jdbcType is OTHER (#5797)
[TD-3766]: fix fsync alter calculation
[TD-3775]: taosdemo interlace rows more than insert rows. (#5819)
[TD-3783]: taosdemo for windows generates rand string invalid. (#5828)

ENHANCEMENTS:
[TD-3079]: use multi-level storage with vnode's wal files
[td-3571]: enable update the vgroup info during super table query.
[TD-3606]: When adding a new node to the cluster, the locale and charset are no longer checked

NEW FEATURES:
[TD-3762]: support us and ms percision for timestamp in JDBC (#5818)

DOCS:
[TD-2577]: "GROUP BY" add "HAVING" support.
[TD-2639]: add keyword "topic".
[TD-2639]: fix version num of long term support release.
[TD-3028]: add service ports section in faq.
[TD-3412]: create docker version for "getting start".
[TD-3412]: fix minor typo.
[TD-3606]: locale & charset options will not be checked when dnode add to cluster.
[TD-3672]: update C# connector environment support.
[TD-3754]: correct the meaning of slimit option.
[TD-3755]: describe the columns num limitation in selecting.

TEST:
[TD-2986]: add demo example into CI
[TD-3676]: add test case
[TD-3677]: test pr message 1
[TD-3677]: test pr message 2
[TD-3677]: test pr message 3
[TD-3796]: test null value in JDBC-JNI

ver-2.0.19.1

Release Notes

FIX BUGS:
[TD-3601]: fix early 1970 time problem
[TD-3534]: fix TD-3534
[TD-3465]: fix TD-3465
[TD-3298]: fix coverity scan error
[td-3662]: fix invalid write caused by top/bottom query.
[TD-3580]: taosdump support human readable time format. (#5674)
[TD-3636]: taosdemo disorder rework. (#5671)
[TD-3660]: taosdemo gracefully exit if super table not exist. (#5670)
[TD-3657]: sdbUpdateMnodeRoles before check mnodeAllOnline
[TD-3458]: Fix the bug of losing tables in multiple replicas
[TD-3653]: taosdemo json parameter cleanup. (#5665)
[TD-3641]: fix interlace timestamp step issue. (#5654)
[TD-3642]: fix staging directory resource leak
[TD-3417]: remove.sh stop and delete the nginxd.service for enterprise edition (#5617)
[TD-3612]: fix vnode write msg double free issue
[td-3457]: fix the bug that cancel request failed to stop query at vnodes.
[td-3571]: fix null value filter bug for bool type.
[TD-3314]: new staging directory for deleting vnodes
[TD-3284]: taosdemo support fixed value tag. (#5632)
[TD-3598]: cleanup few code lines. (#5622)
[TD-3591]: rework limit and offset logic. (#5618)
[TD-3589]: taosdemo need to use db before query. (#5612)
[TD-3577]: taosdemo print stb insert interval. (#5610)
[TD-3592]: fix dnode ID syntax in drop dnode <dnode_id>
[TD-3576]: taosdemo print query times. (#5609)
[TD-3581]: fix uniq/dnode/remove2.sim step3
[TD-3449]: fix drop if not exists error
[TD-3544]: move query times detect to query meta file parse. (#5597)
[TD-3546]: fix taosdemo quer crash as index variable mistake. (#5598)
[TD-3524]: taosdemo query multithreading workaround. (#5587)
[TD-3185]: default numOfCommitThreads to 4, show in cfg template
[TD-3478]: increase thread num of table creation same as insert… (#5577)
[TD-3472]: fix query times determination miss. (#5576)
[TD-3321]: describe stb with better logic. (#5559)
[TD-3349]: maxSQLLength <- TSDB_MAX_ALLOWED_SQL_LEN; minTablesPerVnode, tableIncStepPerVnode <- 100
[TD-3357]: fix child table count if exists. (#5542)
[TD-3433]: fix child table count issue. (#5552)
[TD-3407]: print more info to result file. (#5538)
[td-3391]: fix invalid error msg.
[TD-3431]: fix taosdemo cmdline incorrect arguments. (#5536)

ENHANCEMENTS:

NEW FEATURES:
[TD-3410]: support nutz framework (#5600)
[TD-3402]: taosdemo version. (#5574)
[TD-3036]: syncdb <db_name> replica;
[td-3036]: support the db sync operator.

DOCS:
[TD-2639]: fix minor typo.
[TD-3649]: fix minor typo.
[TD-3649]: update compatibility about HuaWei EulerOS.
[TD-3645]: add description about dimension microsecond in timestamp.
[TD-2518]: timestamp add support for time before year 1970.
[TD-3624]: fix minor typo.
[TD-3573]: add timezone section in faq.
[TD-2639]: add descriptions about database options that can be altered.
[TD-2639]: add a little space for better display format.
[TD-2639]: fix bold text in table title.
[TD-2639]: add detail about firstEp.
[TD-2639]: fix minor typo.
[TD-2639]: update memory size estimation.
[TD-3430]: cmake minimal version is 2.8.12.x.
[TD-2639]: clarify the length limitation of tags.

TEST:
[TD-3588]: update test case
[TD-3602]: update perf test script
[TD-3474]: add test case
[TD-1139]: add c examples into CI
[TD-3413]: make docker cluster support enterprise
[TD-3274]: add test case for after 1970 years

ver-2.0.18.0

Release Notes

FIX BUGS:
[TD-3353]: solve race condition coredump
[TD-3320]: fix sync coredump
[TD-3370]: fix used disk size, show acctual used instead of non-avail to current user
[TD-3369]: fix taosdemo invalid write valgrind reports. (#5496)
[td-3361]: fix crash caused by nchar type filter.
[TD-3356]: fix bug regarding limit offset with exist child table. (#5495)
[TD-3357]: fix child table count if exists. (#5488)
[TD-3355]: Fix invalid table id problem caused by idpool
[td-3361]: nchar tag filter caused client crash.
[TD-3337]: [balance] fix pVgroup->pDb NULL pointer crash
[TD-3332]: vnode report status if not closing instead of not ready
[td-3338]: query data before 1970-1-1 00
[td-3318]: fix crash caused by empty stddev query.
[td-3183]: fix unsigned number arithmetic calculation with sort option caused crash.
[td-3331]: print timestamp format error.
[td-3315]: enable insert timestamp in the format of string '1970-1-1 8
[td-3313]: fix join bug

ENHANCEMENTS:

NEW FEATURES:
[TD-3082]: jdbc connector support unsigned tinyint, smallint, int, bigint (#5447)
[TD-3192]: support child table limit and offset.
[TD-3192]: support child table limit and offset.

DOCS:
[TD-2639]: fix link url detail.
[TD-2354]: need reboot to take effect when alter CACHELAST option.
[TD-2639]: improve expression of some sentences.
[TD-3363]: fix typo.
[TD-3352]: move "quick run" section into "install" part.

[TD-2639]: clarify "now" function usage when insert multi-rows.
[TD-2639]: clarify estimation of memory requirement.
[TD-3336]: update description about "make install" and start service.

TEST:
[TD-3365]: update test case
[TD-3365]: add test case for query filter on tag type
[TD-3316]: add testcase for taosdemo child table limit and offset.
[TD-1002]: add test case for double type

ver-2.0.17.0

FIX BUGS:
[TD-3154]: fix invalid write
[TD-3096]: fix query dead lock
[TD-3075]: fix SBlockCol offset overflow
[TD-3147]: support insert interval. stb case passed.
[TD-3147]: support insert interval. use seperate func for normal table write.
[TD-3177]: fix demo.c checking result error mistake.
[TD-3171]: response error code if any
[TD-3142]: fix JDBC-RESTful back ResultSet with null Type
[TD-3147]: support insert interval. refactor.
[TD-3147]: support insert interval. support no-stb in middle.
[TD-3147]: support insert interval. support no-stb in middle.
[TD-3147]: support insert interval. merge upstream.
[TD-3147]: support insert interval. json works.
[TD-3110]: TSDB_MIN_WAL_LEVEL <- 0 to allow db wal no log
[TD-3167]: fix cannot use chinese charset in docker images
[TD-3158]: fix http column_meta test cases
[TD-3158]: replace head_type with column_meta in http response
[TD-3147]: support insert interval instead of insert rate. cleanup
[TD-3147]: support insert internal instead of insert rate.
[TD-3043]: allow monitor db table to be dropped & altered
[TD-3160]: fix c demo program compile issue.
[TD-3147]: change insert rate to insert interval.
[TD-3042]: fix unsigned to signed conversion with serverPort
[TD-3124]: stop & free TAOS_RES *result post http queue shutdown
[td-3141]: fix the crash of taosd caused by a percentile query on the unsigned numeric data type.
[TD-3113]: remove curl from TDengine. fix linux compile issue.
[TD-3113]: remove curl from TDengine. fix windows compile issue.
[td-3016]: fix sum error for unsigned data type.
[TD-3117]: fix taosdemo coredump led by cntDelay.
[TD-2183]: fix coverity scan issue in taosdemo and taosdump.
[TD-3107]: handle Too many sync fwd infos error crash with batch create table
[TD-2210]: use LWP tid. remove few darwin-related code.
[TD-3113]: remove curl from TDengine. fix compile for mac
[TD-2210]: use LWP tid. fix assertion on mac.
[td-3016]: fix unsigned sum error.
[TD-2008]: min(tsHttpMaxThreads) <- 2, default(tsHttpMaxThreads) <- half of tsNumOfCores
[TD-3073]: fix syncing role not displayed issue
[TD-3085]: support insert speed info.
[td-3009]: diff can not be applied to unsigned numeric data type.
[td-3001]: fix tag filter bug in case of unsigned number existing.
[td-3021]: fix the sql of creating table parsing failed if more than one space exists.
[td-3027]: fix bugs in alter table by adding unsigned tags.
[td-3003]: fix the bug in alter table.
[td-3012]: fix error of the leastsquares in handling unsigned data.
[td-3017]: fix bug in top/bottom query on unsigned data type.
[td-3018]: fix bug in twa query on unsigned data type.
[td-3013]: fix bug in unsigned bigint max/min query.
[TD-3064]: fix wal file size(>2G) overflow with int32_t
[TD-3068]: When the creation of log file fails, the length of old log grows infinitely
[TD-3061]: fix compile issue for arm32 and windows.
[TD-2984]: combine taosdemo and taosdemox. add perf statistics.
[TD-3037]: disable balance for enterprise user.
[TD-3038]: fix incorrect disk free size calculation
[TD-2984]: combine taosdemo and taosdemox. fix ansi escape for windows.
[TD-3031]: fix NULL parser crash
[td-3014]: fix error in spread function when applying to unsigned values.
[td-3035]: fix bug in projections query on super table with filter condition.
[TD-2984]: combine taosdemo and taosdemox. modify test case for new schema.
[TD-2999]: [http] fix NULL parser crash
[TD-2984]: combine taosdemo and taosdemox. solve windows build issue.
[TD-2996]: reset pContext->singleCmd to zeroes when httpReleaseContext(pContext, true)
[TD-2982]: disable rpmbuild auto detect dependency
[TD-2969]: fix rust example submodule issue.

ENHANCEMENTS:
[TD-3158]: add head_type fileds with RESTful API
[TD-3044]: log check global cfg completed to grep count start times
[TD-2955]: [wal][v2] checksum whole wal record instead of just head

NEW FEATURES:
[TD-3173]: java taosdemo can execute one sql statement by commandline
[TD-3148]: make build system detect host arch.
[TD-3148]: make build system detect host arch. add other variables.
[TD-3148]: make build system detect host arch. detect amd64 and x86
[TD-3148]: make build system detect host arch. detect aarch32
[TD-2868]: JDBC-RESTful support PreparedStatement and addBatch
[TD-2868]: JDBC-Restful supported PreparedStatement
[TD-2971]: make python connector support unsigned int. fix None determine.

DOCS:
[TECO-43]: transfer Chinese docs to grav cms system.
[TD-3157]: update readme regarding host arch detecting.
[TD-2639]: fix title number in faq page.
[TD-2639]: fix minor typo about EndPoint options.
[TD-2008]: update default value for option httpMaxThreads.
[TD-3114]: refine centos environment package list
[TD-2639]: add description about normal node can redirect to mnode to provide mnode EP list.
[TD-2639]: clarify keyword stable support relate to system version.
[TD-2639]: Binary column should only store ASCII string.
[TD-2639]: fix minor typo.
[TD-2354]: describe option for caching table last row.
[TD-2639]: fix link to replica doc.
[TD-2639]: fix case sensitive things.
[TD-2423]: allow create table from super table with just specific tag columns.
[TD-2639]: move insert example to be the right place.
[TD-203]: emphasize the best practice about connection sharing in multi threads.
[TD-2568]: describe new commands about client log management.
[TD-2863]: change the unit of measurement for config tsQueryBufferSize.

TEST:
[TD-1977]: add query unit test into CI
[TD-3155]: add test case
[TD-3154]: update test case
[TD-3069]: add test case
[TD-2953]: add jdbc cases into CI
[TD-2423]: add test case
[TD-2977]: add test case
[TD-2846]: update docker cluster scripts

ver-2.0.16.0

Release Notes

FIX BUGS:
[TD-2887]: fix possible race condition coredump
[TD-2962]: fix pContext NULL crash
[TD-2886]: change the error code if the table has been removed and created again with different table schema before issuing query to a vnode.[TD-2910]: fix onlineDnodes > totalDnodes issue
[TD-2643,TD-2925]: update sim test case and JDBCDemo doc
[TD-2925]: rename keep2,keep1 -> keep1,keep0
[TD-2936]: change default path to follow mac standard.
[TD-2923]: Not show databases in dropping
[TD-2822]: fix invalid result set pointer bugs
[TD-2875]: comment out stderr print to make crash_gen no Killed
[TD-2918]: delet stable in mnode first before send dnode drop stable msg
[TD-2402]: remove WINDOS macro related code in ttimer
[TD-2402]: set rows <- 1 constantly when update http sql return success
[TD-2901]: fix bug taosdemo with mono compiled does not exit.
[TD-2402]: set rows <- 1 constantly when update http sql return success
[TD-2885]: fix memory leak.
[TD-2893]: fix http invalid url error typo.
[TD-2875]: use monotonic clock source to fix leap-second issue

ENHANCEMENTS:

NEW FEATURES:
[TD-2931]: add -y parameter to skip prompt.
[TD-2771]: python version taosdemo. add native interface
[TD-2005]: add ErrorNumber in JDBC driver
[TD-2891]: get process cmdline by pid on mac.
[TD-2555]: super table query support stddev query.

DOCS:
[TD-2639]: fix typo in example of alter table tags.
[TD-2639]: fix software version number about STDDEV() on super table.

TEST:
[TD-2568]: add test case
[TD-1351]: add test case
[TD-2671]: add test case for STABLE
[TD-2850]: add test case
[TD-2801]: add test case

ver-2.0.15.0

Release Notes

FIX BUGS:
[TD-2873]: fix JdbcRestfulDemo.java compile issue.
[TD-2541]: optimized the connection pool demo codes
[TD-2597]: fix Druid and HikariCP configurations
[TD-2793]: fix -p option of taos.exe
[TD-2845]: new -V option to taos.exe
[TD-2827]: fix JDBC-RESTful resultSet and restSetMetaData bugs
[TD-2839]: set tsOfflineThreshold max <- 86400 * 365
[TD-2839]: fix tsOfflineThreshold code comments
[TD-2832]: use httpDecodeUrl to parse reserved characters after percent-encoding
[TD-2696]: fix RFC3339 timestamp bug.
[TD-2790]: fix the bug that tableMeta is not updated if parse error occurs.
[TD-2445]: dump toasd process cfgs
[TD-2805]: null pointer checking
[TD-2808]: fix http password len
[TD-2794]: fix authentication failed with changed password
[TD-2794]: fix authentication failed with changed password
[TD-2718]: new create multiple tables test cases
[TD-2490]: add check for full table name.
[TD-2697]: fix buffer overflow
[TD-2769]: make nodejs connector use napi to support v10 and v12.
[TD-2769]: lock ref-napi version to 1.5.2.
[TD-2788]: fix two telemetryReporting options in taos.cfg.
[TD-2769]: update package json files.
[TD-1600]: return error code to client if importing data from file failed.
[TD-2778]: fix invalid read during merge data in both buffer and data files.
[TD-2777]: fix potential risk to execute rm -rf /
[TD-2769]:nodejs 12+ adapt
[TD-2247]: fix invalid sql caused client crash.

ENHANCEMENTS:
[TD-2785]: Allow to judge the status of sync and arbitrator ports
[TD-2759]: remove 1s additional check peer conn timer interval

NEW FEATURES:
[TD-109]: support mac compile with xcode11.4 in travis CI. enable in .travis.yml
[TD-109]: support mac compile with xcode11.4 in travis CI. redefine MSG_NOSIGNAL
[TD-2339]: interpolation can be applied along with the time window.
[TD-2776]: add stable infos in getTables method
[TD-2635]: support next fill option.

DOCS:
[TD-1413]: enterprise edition support multi-layer storage now.
[TD-2571]: add new keyword DISTINCT to select different values of tag column in super table.
[TD-2852]: add Mac platform compiling section to the README.md.
[TD-2829]: refine Windows compiling section of README.md
[TD-2639]: twa() do not support super table in current version.
[TD-2639]: remove unessential emphasis.
[TD-2639]: fix indent of doc.
[TD-2639]: fix escape code type error.
[TD-2671]: Super Table will use keyword "STABLE" since now.
[TD-2639]: remove one misplaced doc.
[TD-2639]: distinguish the concept Arbitrator and the command tarbitrator.
[TD-2757]: fix description about VNode mem cache.
[TD-2775]: update faq regarding UPDATE parameter.
[TD-2763]: remove outdated description.
[TD-2555]: STDDEV() support calculation on super table.
[TD-2639]: fix minor typo.
[TD-2639]: fix a code format.
[TD-2639]: fix minor typo.
[TD-2775]: add update to faq, fix minor typo.
[TD-2775]: add update to faq.

TEST:
[TD-2672]: optimized the JDBC test cases
[TD-2700]: add test case
[TD-2635]: add test case
[TD-1024]: add test case
[TD-2720][TD-2247]: add test case
[TD-2451]: add test case
[TD-2695]: change jdbc unit test cases

ver-2.0.14.0

Release Notes

FIX BUGS:
[TD-2758]: database may always in syncing state because a node is offline
[TD-2752]: check if the FILE pointer is valid or not.
[TD-2756]: correct docstring in taos.cfg

ENHANCEMENTS:
[TD-2606]: enlarge TSDB_MAX_WAL_SIZE from 2M to 3M

NEW FEATURES:

DOCS:
[TD-2632]: add batch size suggestion for batch creating tables.
[TD-2720]: fix description for account name length limit
[TD-2680]: "show dnodes" will include arbitrator node
[TD-1866]: describe the relationship of taos_consume & taos_free_result

ver-2.0.13.0

Release Notes

FIX BUGS:
[TD-2604]: fix coredump
[TD-2583]:function min gets result value zero when column values contain NULL
[TD-2429]: data may be lost during load balancing
[TD-2557]:insert from file failed after changing stable
[TD-2587]: fix bugs introduced by refactor.
[TD-2559]: taos can't cancel stable query when fetching data
[TD-2302]: fix nodejs exception when query a null value
[TD-2563]: fix invalid write caused by top/bottom query at client side.
[TD-2562]: fix bug in twa query.
[TD-2457]: check the invalid order by clause for top/bottom query.
[TD-2560]: client crash when execute 'show tables like'
[TD-2550]: fix nodejs connector of td2.0-connector cannot use in 2.0.8.0 or later
[TD-2511]: DB new option cacheLastRow

ENHANCEMENTS:
[TD-2606]: double TSDB_MAX_WAL_SIZE from 1M to 2M
[TD-2561]: new field clusterId for SConnectRsp
[TD-2378]: optimize the client memory requirement.
[TD-2512]: support in memory cached last row query.

NEW FEATURES:
[TD-2502]: force version checking with rpc request messages

DOCS:
[TECO-40]: add video link to documentation markdown, change FAQ to list

TEST:
[TD-2585]: migrate 4 sim cases to python to improve speed
[TD-2551]: get insert delay values for taosdemo performance

ver-2.0.12.0

FIX BUGS:
[TD-2548]:wrong error message is showed when taos connect failed
[TD-2477]:taosd crash when executing queries
[TD-2538]: crash when sql has limit & offset
[TD-2534]: fix crash on null pointer parser
[TD-2528]: messy characters in alert msgs
[TD-2487]: create stble with a wrong type tag but report length too long
[TD-2464]: validate maxTablesPerVnode and reset to minTablesPerV…
[TD-2484]: use IPv4's AI_INET instead of AI_UNSPEC
[TD-2550]: fix nodejs bug in new version.
[TD-2482]: fix bug in the skiplist iteration during query processing.
[TD-2471]: fix the bug during the removal of elements in trashcan.
[TD-2488]: fix super table bug.

ENHANCEMENTS:
[TD-2434]: reduce the memory requirement during super table interval query.

NEW FEATURES:

DOCS:
[TECO-39]: continue refine connector page.

TEST:
[TD-2488]: add test case
[TD-965]: add test case for TWA