CPU intensity evaluation method for joint operation in database system

A CPU intensity evaluation method for joint operation in a database system comprises the following steps of S1. initializing the residue of unit time (tleft=1), completing the time (tjoint_IB_left) used for jointing input buffer (IB), and filling the joint time (tjoint_OB_left) of output buffer (OB) and the like parameters; S2. entering into S3 if tleft>0, otherwise, terminating and outputting tcpu; S3. entering into S4 if tleft is enough to completing the joint of IB, otherwise entering into S8; S4. entering into S7 if the jointing result of IB is not enough to fill OB; S5. jointing IB until the OB is full filled, asynchronously reading in IB', updating tcpu, getting usable OB and entering into S2, if the jointing result of IB is more than to fill OB; S6 getting usable IB and OB, updating tcpu and entering into S2, if the jointing result of IB is just enough to fill OB; S7. completing joint of IB, asynchronously reading in IB' and writing out OB', getting usable IB, updating tcpu and entering into S2; S8. jointing IB until OB is full filled, asynchronously reading in IB', writing out OB', taking usable OB, updating tcpu and entering into S2, if tleft is enough to full connect OB, otherwise entering into S9; and S9. jointing IB until tleft is equal to 0, writing the result into OB, updating tcpu and entering into S2.