First of all - welcome to Adobe Analytics! I hope your experience has been great so far, don't hesitate to reach out to the community here with questions (like you already have) or check out our YouTube channel for quick training opportunities:
Depending on whether you're using GA free or GA 360/Premium, you may not be able to access all of your historical data. And to be honest, you may not want to do this at all as it's time-consuming, limiting, and potentially expensive.
If you were using GA free, there’s no way to get a complete and granular export of the data. Google samples the data and it will be very difficult to get several years’ worth of data out of the platform. Of course, this depends on the level of granularity that you're looking to extract. If it’s something simple like Pageviews, Visits, Visitors per month, then that’s not too painful. If you need revenue, downloads, etc, then it’s much tougher to get at the data. If you need pathing/flow reports, that’s extremely difficult, but maybe possible if you have GA 360/Premium. If you need visitor data from Google Free tied to the exact visitor data from Adobe, once installed, that’s virtually impossible.
My recommendation is to be simple: PV counts and one KPI at the monthly level; daily if you absolutely need it.
Once you've decided the granularity, metrics, and dimensions that you want to import, the next step after exporting it is pushing the data IN to Adobe.
The best way to push the data into Adobe is via the Data Insertion API or via Data Sources. Keep in mind this higher level of granularity data should be used for correlation (not causation). And true analysis of your old data should be done in GA, whereas the historical import should be used directionally.
Keep in mind that every 'row' of data that you import (via Data Sources or API) counts towards your server calls.
I hope that helps! And thanks again for choosing Adobe.
Thanks. This is helpful. Then my next question is, when I insert the data via API or data source, could data from Google analytics integrate with Adobe data well? Is there any metric significantly different from adobe and google analytics? Sorry for asking this question. I am new to both.
Happy to help. Here's a post I wrote a couple years ago on that topic:
Short answer to your question is - this probably isn't worth your time. The data can't be fully integrated and won't be a seamless integration. The tools vary way too much, unfortunately. My preferred recommendation, if possible, is to run the two tools in parallel and slowly phase out GA as your team successfully migrates to Adobe.