For PL/SQL connection, 64-bit Oracle has recently changed to 64-bit Win7, and oracle has also changed to 64-bit 11g. After the change, we found that the plsql cannot load the database at all. There are also various changes to version Shenma on the Internet. I don't want to change the version, so I figured out how to make plsql load 64-bit files. Finally, we found a simple problem that could not connect to the database. The steps for organizing www.2cto.com are as follows: 1. download and install the 64-bit Oracle 11g R2 (my version is the second version downloaded from the oracle official website, simply install the database. 2. Download the Oracle 11g 32-bit client, castrated the green version, and decompress it. 3. The key step is to copy a directory under the root directory of the database installation .. \ product \ 11.2.0 \ dbhome_1 \ NETWORK to the Oracle client directory. When extracting the package, there should be a NETWORK folder to overwrite it. 4. Download and install PL/SQL 8.0. During the installation process, PL/SQL automatically detects the Client Directory and loads the corresponding dll, which is the directory decompressed by Oracle, decompress the directory \ oci. dll. If Automatic Detection is not performed, skip this step. I am using a green castrated version, so it cannot be identified. Just configure it later. Open PL at www.2cto.com, and set Oracle Home and OCI library without logging on to Tools> Preferences Connection. 5. Start Oracle Database Service OracleOraDb11g_home1TNSListener and OracleServiceORCL. the user logs on and connects to PL/SQL! In fact, after the modification, plsql loads a 32-bit oracle client, and the client then connects to the database server. Since plsql directly loads a 64-bit oracle client (which is provided by the server and installed when oracle is installed), the file loading fails and the connection fails. However, 32-bit PL/SQL is much faster than Oracle's built-in SQL Developer. Author l6259710