The information someone else posted on this site may help you understand how background searches work. CIC and the visa office don't even know how long it will take to complete. Therefore your best mechanism is to try to be patient. i know you waited long already, but know that good news is coming, since your interview was positive.
Background Check is bisecting in two:
1. Documentation Checks:
Our background check is done at the CHC stage. It commences the moment our file gets the 1st BFD by the VO. An indicator of which is the e-CAS that shows "In Progress". All docs been checked & our spousal sponsorships being tallied against the MI, if the VO finds our case 'eligible' for Canadian PR, the file becomes 'Accepted'; and then it goes for standard background checks, Genuineness of relationship ,Adaptability, Qualitative, Considerations etc.
The process involves many things. If our case file is well presented and the enclosures vouch the quality-quantity, adequate docs etc. The VOs have a way with that, they are experienced enough to ascertain the logical disposition of our case. But, if there are any concerns of his/her, s/he is likely to ask for additional docs, do further scrutiny by any means and ask for an Interview.
2. Security & Criminality Checks:
A part of the b/ground checks is the 'Security Check'. It commences after our med results are submitted or received to the CHC. This is a major activity -mainly concerning our 'safe inclusion' into the Canadian Soil; in terms of, Political, Socio-Economical, Anti-Social disposition, perceived Threat to Canada's integrity etc.
This is a serious & time-consuming stage, involving many agencies, including CSIS, Interpol, CBSA, Database Checking & touch-base with Local Police. Many things are considered here... the Number of countries visited, Applicant coming from 'certain' countries, ex-Servicemen (including Law Enforcement services), Prolonged stay in a country w/out sufficient docs to prove cause, frequent traveling to certain targeted countries, your *Name (?), Inter-Religion/Nationality Marriages etc.
If everything is simple & straight, the file soon gets into the 'final review' stage. If there are any 'red flags', our case goes into a 'spin'. Then our file might go to the local Police/CID agencies; the outcome/timeframe of which is beyond the control of CIC. And thereby the timeframe can be anything [sometimes beyond 1yr]. But, usually this stage should be over by 5 months max. However, a point to be noted is that we can also be called for an Interview [at this stage], due to this reason.
-Results: Only upon security clearance we receive the PPR.
-Timeframe: Around 2-6 months. Avg. 3 months. Sometimes PPR is clubbed with Meds
-Ecas: Still 'In Process', but 'Med Results Recd.' inside.