Udb server interface
aq_udb [-h] Global_Opt Mnt_Spec|Order_Spec|Export_Spec
Global_Opt:
[-verb] [-stat] [-test]
[-server AdrSpec [AdrSpec ...]] [-local]
Mnt_Spec:
-crt[,AtrLst] DbName |
-alt[,AtrLst] DbName |
-clr[,AtrLst] DbName[:TabName] |
-inf[,AtrLst] DbName [-o[,AtrLst] File] |
-probe[,AtrLst] DbName
Order_Spec:
-ord[,AtrLst] DbName[:TabName] [ColName ...]
Export_Spec:
-exp[,AtrLst] DbName[:TabName] |
-cnt[,AtrLst] DbName[:TabName] |
-scn[,AtrLst] DbName[:TabName]
[-seed RandSeed]
[-var ColName Val]
[-pp TabName
[-bvar ColName Val]
[-eval ColName Expr]
[-filt FilterSpec]
[-goto DestSpec]
[-del_row | -del_key]
-endpp]
[-bvar ColName Val]
[-eval ColName Expr]
[-filt FilterSpec]
[-goto DestSpec]
[-del_row | -del_key]
[-mod ModSpec [ModSrc]]
[-sort[,AtrLst] ColName ...]
[-lim_key Num] [-lim_rec Num] [-key_rec Num] [-top Num]
[-o[,AtrLst] File] [-c ColName [ColName ...]]
aq_udb is a client of the Udb server.
It is used to send command to the server (or a pool of servers)
to manipulate and/or export the data held by the server.
It can also instruct the server to clear a portion or all of the held
data.
Data manipulation can be done using builtin options or through a custom module that is dynamically loaded on the server side.
Note: Data import to the Udb server is done by aq_pp.
-testTest command line arguments and exit.
If specified twice (-test -test), a more throughout test will be
attempted. For example, the program will try to
connect to Udb in test mode.
-verb-statPrint a record count summary line to stderr at the end of processing. The line has the form:
aq_udb: rec=Count
-server AdrSpec [AdrSpec ...]AdrSpec has the form IP_or_Domain[|IP_or_Domain_Alt][:Port].
See udb.spec for details.-local-crt[,AtrLst] DbNameCreate a database explicitly. Normally, a database is created automatically
during an import (see aq_pp).
However, it is a good idea to perform this create operation anyway in case
the import is not performed.
DbName is the database name (see Target Database).
Note that it is not an error to create a database that already exists as
long as the database definition is identical.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).-alt[,AtrLst] DbNameAlter the spec of database DbName (see Target Database).
The database must already exist (e.g., created via -crt).
Currently, only the Var vector spec can be altered,
all other tables and vectors must be the same as before.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).The values of columns that exist in both the old and new specs are preserved. New columns are initialized with 0/blank.
-clr[,AtrLst] DbName[:TabName]Clear an entire DB or remove/reset the data of a table/vector.
DbName is the database name (see Target Database).
TabName is a table/vector name in the database.
Specific clear actions are:
TabName is “var”), its columns are reset
to 0/blank.TabName is not given or if it is a ”.” (a dot), everything will be
cleared - all keys, tables, vectors, the Var vector and the database
definition will all be removed.Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).-inf[,AtrLst] DbNameGet the primary key counts and table/vector row counts of database DbName
(see Target Database). It differs from -cnt in these ways:
All table/vectors row counts are output. The output has this form:
"pkey","var","TabName1","TabName2",...,"VecName1","VecName2",... num,num,num,num,...,num,num,...
Processing rules (e.g., filters) are not supported.
Much faster - the counts are cached in memory, no database scan needed.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).asis - Normally, the results from all the servers are combined to
produce a single row of counts. With this attribute, the individual
servers’ counts are output, producing one row of counts per server.-probe[,AtrLst] DbNameCheck if the servers associated with database DbName
(see Target Database) are heathly and that
the database has been defined on the servers.
DbName is not defined,
the exit code will be non-zero.
Usually, an error message will be printed on stderr.Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).-ord[,AtrLst] DbName[:TabName] [ColName ...]Sort the keys in a DB or sort the records in a table for each key.
This will alter the data order in the DB.
This operation is done internally, no output will be generated.
The default sort order is ascending.
DbName is the database name (see Target Database).
TabName is the target table to sort.
ColNames are the desired sort columns.
If TabName or ColName is not given:
TabName given, ColName not given -
TabName will be sorted by its “TKEY” column
(see udb.spec).TabName not given or is a ”.” (a dot), ColName not given -
Every table in DbName with a “TKEY” will be sorted by its “TKEY”.TabName not given or is a ”.” (a dot), ColName given -
Each ColName must be a primary key column. This will sort the data
by their keys on a per server basis. If the database is distributed over
a server pool, the keys are not sorted across servers.`Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).ncas - Do case insensitive match (default is case sensitive).
For ASCII data only.dec - Sort in descending order (default is ascending).-exp[,AtrLst] DbName[:TabName]Export data.
DbName is the database name (see Target Database).
TabName is a table/vector name in the database.
If TabName is not given or if it is a ”.” (a dot), the primary keys
will be exported.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).asis - This attributes only affects the result of a Var vector
export. Normally, the results from all the servers are combined to
produce a single row of Var values. With this attribute, the individual
servers’ values are output, producing one row of values per server.seg=N1[-N2]/N[:V] - Only export a subset of the data by selecting
segment N1 or segments N1 to N2 (inclusive) out of N segments of
unique keys based on their hash values.
For example, seg=2-4/10 will divide the keys into 10 segments and
export segments 2, 3 and 4; segments 1 and 5-10 are skipped.
Optional V is a number that can be used to vary the sample selection.
It is zero by default.-cnt[,AtrLst] DbName[:TabName]Count the unique primary keys in database DbName (see Target Database).
If TabName is given, count the rows in the table/vector as well.
Normally, use this option when the counts are processing rules dependent
(e.g., filters); otherwise, use -inf since it is much faster.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).asis - Normally, the results from all the servers are combined to
produce a single set of counts. With this attribute, the individual
servers’ counts are output, producing one set of counts per server.seg=N1[-N2]/N[:V] - Only count a subset of the data by selecting
segment N1 or segments N1 to N2 (inclusive) out of N segments of
unique keys based on their hash values.
For example, seg=2-4/10 will divide the keys into 10 segments and
count segments 2, 3 and 4; segments 1 and 5-10 are skipped.
Optional V is a number that can be used to vary the sample selection.
It is zero by default.-scn[,AtrLst] DbName[:TabName]Scan data only. No output will be produced.
This option is typically used along with certain data processing rules
(see Data Processing Steps) and/or a data processing module (see -mod).
DbName is the database name (see Target Database).
TabName is a table/vector name in the database.
If TabName is not given or if it is a ”.” (a dot), the primary keys
will be scanned - this is typically used with -pp rules.
Optional AtrLst is a comma separated list containing:
spec=UdbSpec - Set the spec file directly (see Target Database).-seed RandSeed$Random
-eval builtin variable.-var ColName ValSet the value of the Var vector column ColName to Val.
A Var vector must be defined in the Udb spec file and ColName
must be a column in that table.
See udb.spec for details.
Note that a string Val must be quoted,
see String Constant spec for details.
Example:
$ aq_udb ... -var Var1 0 ...
-bvar ColName ValSame as -var except that the column is set to Val repeatedly
as each key is processed before other processing rules are executed.
Note that a string Val must be quoted,
see String Constant spec for details.
This rule can also be used within a -pp group. In this case,
ColName is set to Val as each key is processed before other
pre-processing rules are executed.
See Data Processing Steps for details on these usages.
Example:
$ aq_udb ... -pp -bvar Var1 0 ...
-eval ColName ExprFor each row in the table/vector being exported/counted/scanned,
evaluate expression Expr and place the result in a column identified
by ColName. The column can be part of the target table or the Var vector.
This rule can also be used within a -pp group. In this case,
the target table becomes the -pp table.
Note that -eval rules inside -pp groups are evaluated before those
for the target table/vector. See Data Processing Steps for details.
Expr is the expression to evaluate.
Data type of the evaluated result must be compatible with the data type of
the target column. For example, string result for a string column and
numeric result for a numeric column (there is no automatic type conversion;
however, explicit conversion can be done using the To*() functions
described below).
Operands in the expression can be columns from the target table/vector,
columns from other vectors, columns from the Var vector,
constants, builtin variables and functions.
VecName.ColName format. For the Var vector, VecName is optional
unless ColName also exists in the target.ToIP(), ToF(), ToI() and ToS().Builtin variables:
$Random$RowNum$CurSec$CurUSecStandard functions:
See aq-emod for a list of supported functions.
Example:
$ aq_udb -exp mydb:Test -eval c_delta 'c1 - c2'
-filt FilterSpecFor each row in the table/vector being exported/counted/scanned,
evaluate FilterSpec and use the result to determine whether to
keep the data row.
The result can also be used in a -if/-elif/-endif for
Rule Execution Controls.
This rule can also be used within a -pp group. In this case,
the target table becomes the -pp table.
Note that -filt rules inside -pp groups are evaluated before those
for the target table/vector. See Data Processing Steps for details.
FilterSpec is the filter to evaluate.
It has the basic form [!] LHS [<compare> RHS] where:
! negates the result of the comparison.
It is recommended that !(...) be used to clarify the intended
operation even though it is not required.VecName.ColName format. For the Var vector, VecName is optional
unless ColName also exists in the target.==, >, <, >=, <= -
LHS and RHS comparison.~==, ~>, ~<, ~>=, ~<= -
LHS and RHS case insensitive comparison; string type only.!=, !~= -
Negation of the above equal operators.&= -
Perform a “(LHS & RHS) == RHS” check; numeric types only.!&= -
Negation of the above.& -
Perform a “(LHS & RHS) != 0” check; numeric types only.!& -
Negation of the above.More complex expression can be constructed by using (...) (grouping),
! (negation), || (or) and && (and).
For example:
LHS_1 == RHS_1 && !(LHS_2 == RHS_2 || LHS_3 == RHS_3)
Example:
$ aq_udb -exp mydb:Test -filt 't > 123456789'
$ aq_udb -exp mydb:Test -filt 'Eval($Random % 100) == 0'
-goto DestSpecGo to DestSpec. This is uaually done conditionally within a
-if/-elif/-endif block (see Rule Execution Controls for details).
DestSpec is the destination to go to. It is one of:
next_key - Stop processing the current key and
start over on the next key.next_row - Stop processing the current row and
start over on the next row.This rule can also be used within a -pp group. In this case, these additional destinations are supported:
proc_key - Terminate all -pp processings (i.e.,
stop the current -pp group and skip all pending -pp groups)
and start the export/count/scan operation for the current key.next_pp - Stop the current -pp group and start the next one.-del_row[,AtrLst]Delete the current row in the database. No more processing on the current row will be done.
Optional AtrLst is a comma separated list containing:
post=DestSpec - Set the action to take after the delete.
DestSpec is one of:next_key - Stop processing the current key and
start over on the next key.proc_key - Skip all pending -pp groups
and start the export/count/scan operation for the current key.next_row - Start processing the next row. This is the default
behavior.-del_key[,AtrLst]Delete the current key and its associated data from the database. No more processing on the current key will be done.
Optional AtrLst is a comma separated list containing:
post=DestSpec - Set the action to take after the delete.
DestSpec is one of:next_key - Start processing the next key. This is the default
behavior.-pp[,AtrLst] TabName [-bvar ... -eval ... -filt ... -goto ... -del_row ...] -endpp-pp groups one or more -bvar, -eval, -filt, -goto,
-del_row and -del_key actions together.
Each group performs pre-processing on a set of key specific data (e.g., a
table). It is done before the main export/count/scan operation.
See Data Processing Steps for details.
TabName sets the target table/vector for the rules in the -pp group.
It may refer to a table/vector or the primary key set.
To target a table/vector, specify its name.
To target the primary key set, specify a ”.” (a dot).
”.” is a pseudo vector containing the primary key columns.
Optional AtrLst is a comma separated list containing:
post=DestSpec - Set the action to take after all the rows in
the target table has been exhausted.
DestSpec is one of:next_key - Stop processing the current key and
start over on the next key.proc_key - Skip all pending -pp groups
and start the export/count/scan operation for the current key.next_pp - Start the next -pp group. This is the default behavior.The -bvar rules in the group are always executed first. Then the list of -eval, -filt, -goto, -del_row and -del_key rules are executed in order. Rule executions can also be made conditional by adding “if-else” controls, see Rule Execution Controls for details.
-endpp marks the end of a -pp group.
Example:
$ aq_udb -exp mydb:Test1 -pp,post=next_key 'Test2' -goto proc_key
-goto rule will be executed on the first row, causing
execution to jump to export processing; in this way, the post
action is not triggered. However, if Test2 is empty, -goto
is not executed and post is triggered.$ aq_udb -exp Test -pp . -filt 'Eval($Random % 100) == 0' -endpp -filt 't > 123456789'
-endpp is mandatory here to prevent misinterpretation of the
2nd -filt.-mod ModSpec [ModSrc]Specify a module to be loaded on the server side during an export/count/scan operation. A module contains one or more processing functions which are called as each key is processed according to the Data Processing Steps. Only one such module can be specified.
ModSpec has the form ModName or ModName(Arg1, Arg2, ...)
where ModName is the module name and Arg* are module dependent
arguments. Note that the arguments must be literals -
string constants (quoted), numbers or IP addresses.
ModSrc is an optional module source file containing:
.so extension.Without ModSrc, the server will look for a preinstalled module matching
ModName.
-sort[,AtrLst] ColName ...Sort the export result according to the given columns.
Note that only the result is sorted, data order in the DB is not altered.
Use this with -top to get the top ranking results if desired.
Optional AtrLst is a comma separated list containing:
ncas - Do case insensitive pattern match (default is case sensitive).
For ASCII data only.dec - Sort in descending order (default is ascending).-lim_key NumNum unique keys.
This option is intended for data sampling only. The actual result count can
be less than expected if the data is distributed over multiple servers.-lim_rec NumNum records.
This option is intended for data sampling only. The actual result count can
be less than expected if the data is distributed over multiple servers.
Use the -top option if a precise limit is needed.-key_rec NumNum records per unique key.-top NumNum records.-o[,AtrLst] FileSet the output attributes and file for a -inf, -exp or -cnt operation. See the aq_tool output specifications manual for details. If this option is not used with those operations, the result will be written to stdout.
Example:
$ aq_udb -exp mydb:Test ... -o - -c Col2 Col1
-c ColName [ColName ...]Select the columns to output during a -exp operation.
To address columns other than those in the target table/vector, use the
VecName.ColName format. For the Var vector, VecName (Var)
is optional unless a column of the same name also exists in the target.
Shorthands can be used to represent groups of columns from a table/vector:
* or + for all the columns in the target table/vector.
* includes the primary key columns (if any), while +
excludes them.TabName.* or VecName.* or TabName.+ or VecName.+
for all the columns in any applicable table/vector.
* includes the primary key columns (if any), while +
excludes them.In addition, these special forms can also supported:
ColName[:NewName][+NumPrintFormat] - Add ColName to the output.
If :NewName is given, it will be used as the output label.
The +NumPrintFormat spec is for numeric columns. It overrides the
print format of the column (be careful with this format - a wrong spec
can crash the program).^ColName[:NewName][+NumPrintFormat] - Same as the above, but with a
leading ^ mark. It is used to modify the output label and/or format
of a previously selected output column called ColName.
If ^ColName[...] is the first selection after -c, then * will be
included automatically first.~ColName - The leading ~ mark is used to exclude a previously
selected output column called ColName.
If ~ColName is the first selection after -c, then * will be
included automatically first.Example:
$ aq_udb -exp mydb:Test ... -c Test_Col1 ... Test_ColN Var_Col1 ... Var_ColN $ aq_udb -exp mydb:Test ... -c 'Test.*' 'Var.*' $ aq_udb -exp mydb:Test ... -c '*' 'Var.*'
If successful, the program exits with status 0. Otherwise, the program exits with a non-zero status code along error messages printed to stderr. Applicable exit codes are:
A string constant must be quoted between double or single quotes. With double quotes, special character sequences can be used to represent special characters. With single quotes, no special sequence is recognized; in other words, a single quote cannot occur between single quotes.
Character sequences recognized between double quotes are:
\\ - represents a literal backslash character.\" - represents a literal double quote character.\b - represents a literal backspace character.\f - represents a literal form feed character.\n - represents a literal new line character.\r - represents a literal carriage return character.\t - represents a literal horizontal tab character.\v - represents a literal vertical tab character.\0 - represents a NULL character.\xHH - represents a character whose HEX value is HH.\<newline> - represents a line continuation sequence; both the backslash
and the newline will be removed.Sequences that are not recognized will be kept as-is.
Two or more quoted strings can be used back to back to form a single string. For example,
'a "b" c'" d 'e' f" => a "b" c d 'e' f
aq_udb obtains information about the target database from a spec file.
The spec file contains server IPs (or domain names) and table/vector
definitions. See udb.spec for details.
aq_udb finds the relevant spec file in several ways:
spec=UdbSpec attribute
of the main operation option (-crt, -exp, etc.).DbName parameters
of the main operation option (-crt, -exp, etc.).
This method sets the spec file to “.conf/DbName.spec” in the runtime
directory of aq_udb.udb.spec” in the runtime directory of aq_udb.-pp also supports conditional actions using the
-if[not], -elif[not], -else and -endif construction:
-if[not] RuleToCheck RuleToRun ... -elif[not] RuleToCheck RuleToRun ... -else RuleToRun ... -endif
Sypported RuleToCheck are -eval and -filt.
Suppoeted RuleToRun are -eval, -filt, -goto, -del_row and
-del_key.
Example:
$ aq_udb -exp mydb:Test -pp Test -bvar v_seq 0 -if -filt 'flag == "yes"' -eval v_seq 'v_seq + 1' -eval c3 'v_seq' -else -eval c3 '0' -endif
For each export/count/scan operation, data is processed according to the command line options in this way:
-pp group:-pp table. For each row in the table:
post attribute
setting or start the next group by default.