1. A data coordination support apparatus that supports data coordination of a database including a plurality of tables, the data coordination support apparatus comprising:
an information storage unit to store primary key information indicating whether or not each of a plurality of columns included in each of the plurality of tables is designated as a primary key, and attribute information indicating an attribute of data contained in each of the plurality of columns included in each of the plurality of tables;
a table selection unit to select a table being a coordination destination of the data coordination, from among the plurality of tables;
a column identification unit to identify, with respect to each table among the plurality of tables other than the table selected by the table selection unit, a first column designated as the primary key and a second column not designated as the primary key, from a plurality of columns included in a table, based on the primary key information stored in the information storage unit;
a table extraction unit to extract such a table that a third column similar to the first column identified by the column identification unit is included in the table selected by the table selection unit, and a fourth column similar to the second column identified by the column identification unit is included in the table selected by the table selection unit, from tables among the plurality of tables other than the table selected by the table selection unit, based on the attribute information stored in the information storage unit; and
an information output unit to output recommendation information that recommends using a combination of the table selected by the table selection unit and the table extracted by the table extraction unit, in the data coordination, wherein
the table extraction unit, with respect to a table in which two or more second columns are identified by the column identification unit, extracts such a table that the fourth column exists, in the table selected by the table selection unit, individually for a largest number of the second columns.
2. The data coordination support apparatus according to claim 1, wherein
the table extraction unit, with respect to a table in which two or more first columns are identified by the column identification unit, extracts such a table that the third column exists, in the table selected by the table selection unit, individually for all of the first columns.
3. (canceled)
4. The data coordination support apparatus according to claim 1, wherein
the table extraction unit extracts at least two types of tables out of three types of tables, the three types of tables being a table that belongs to a same schema as the table selected by the table selection unit, a table that belongs to a different schema of a same instance as the table selected by the table selection unit, and a table that belongs to a schema of a different instance than the table selected by the table selection unit, and
the information output unit outputs, as the recommendation information, information that recommends using the combination of the table selected by the table selection unit and the table extracted by the table extraction unit, in the data coordination, for each type of the table extracted by the table extraction unit.
5. A data coordination support method that supports data coordination of a database including a plurality of tables, the data coordination support method comprising:
by use of a computer which includes an information storage unit that stores primary key information indicating whether or not each of a plurality of columns included in each of the plurality of tables is designated as a primary key, and attribute information indicating an attribute of data contained in each of the plurality of columns included in each of the plurality of tables, selecting a table being a coordination destination of the data coordination, from among the plurality of tables;
by use of the computer, identifying, with respect to each table among the plurality of tables other than the table selected by the selecting, a first column designated as the primary key and a second column not designated as the primary key, from a plurality of columns included in a table, based on the primary key information stored in the information storage unit;
by use of the computer, extracting such a table that a third column similar to the first column identified by the identifying is included in the table selected by the selecting, and a fourth column similar to the second column identified by the identifying is included in the table selected by the selecting, from tables among the plurality of tables other than the table selected by the selecting, based on the attribute information stored in the information storage unit; and
by use of the computer, outputting recommendation information that recommends using a combination of the table selected by the selecting and the table extracted by the extracting, in the data coordination, wherein
the extracting, with respect to a table in which two or more second columns are identified by the identifying, extracts such a table that the fourth column exists, in the table selected by the selecting, individually for a largest number of the second columns.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
I claim:
1. A phase-locked loop frequency synthesizer comprising;
a reference signal generator for generating a reference signal with a reference frequency;
a voltage controlled oscillator for generating an output signal having an output frequency in response to a control voltage signal received thereby;
a first variable frequency divider connected to said reference signal generator for frequency dividing the reference signal on the basis of a first divisor so as to generate a divided reference signal;
a second variable frequency divider connected to said voltage controlled oscillator for frequency dividing the output signal on the basis of a second divisor so as to generate a divided output signal;
a first controllable synchronous frequency divider connected to said first variable frequency divider for frequency dividing the divided reference signal on the basis of a third divisor upon receiving a frequency dividing control signal so as to generate a first low frequency signal;
a second controllable synchronous frequency divider connected to said second variable frequency divider for frequency dividing the divided output signal on the basis of the third divisor upon receiving the frequency dividing control signal so as to generate a second low frequency signal;
a phase-frequency comparator connected to said first and second controllable synchronous frequency dividers for receiving the first and second low frequency signals therefrom, said phase-frequency comparator comparing the first and second low frequency signals and outputting an adjust signal according to a detected difference therebetween;
a control voltage generating circuit connected to said voltage controlled oscillator and said phase-frequency comparator, said control voltage generating circuit supplying the control voltage signal to said voltage controlled oscillator in response to the adjust signal;
a phase-locked detector connected to said phase-frequency comparator for outputting a phase-locked signal in response to the adjust signal; and
a switching control logic connected to said phase-locked detector, said control voltage generating circuit, said first variable frequency divider, and said first and second controllable synchronous frequency dividers, said switching control logic being operable so as to supply the frequency dividing control signal to said first and second controllable synchronous frequency dividers with reference to the divided reference signal from said first variable frequency divider upon receiving the phase-locked signal from said phase-locked detector.
2. The phase-locked loop frequency synthesizer as claimed in claim 1, wherein each of said first and second controllable synchronous frequency dividers includes:
a first inverter having an input connected to a respective one of said first and second variable frequency dividers, and an output connected to a first node;
a first flip-flop having a first input connected to said switching control logic, a clock input connected to said first node, and an output connected to a second node;
a controllable frequency divider having a first input connected to said first node, a reset signal input connected to said second node, a divider input to receive the third divisor, and an output connected to a third node;
a NAND gate having a first input connected to said second node, a second input connected to said switching control logic, and an output;
a second inverter having an input connected to said third node, and an output;
a second flip-flop having a first input connected to said output of said NAND gate, a clock input connected to said output of said second inverter, and an output;
an OR gate having a first input connected to said third node, a second input connected to said output of said second flip-flop, and an output; and
an AND gate having a first input connected to the respective one of said first and second variable frequency dividers, a second input connected to said output of said OR gate, and an output connected to said phase-frequency comparator.
3. The phase-locked loop frequency synthesizer as claimed in claim 1, wherein R denotes the first divisor, N denotes the second divisor, Fref denotes the reference frequency, Fvco denotes the output frequency, and Fpfd denotes an operating frequency of said phase-frequency comparator, R, N, Fref, Fvco, Fpfd having a relation in which Fpfd{fraction (FrefR)}{fraction (FvcoN)}.
4. The phase-locked loop frequency synthesizer as claimed in claim 3, wherein, when the second divisor (N) is a fraction, the third divisor (M) is an integer and is a multiple of a denominator of the second divisor (N).